WO2001006853A2 - Novel juvenile hormone analogues and their use as antifouling agents - Google Patents

Abstract

The use of juvenile hormone analogues (juvenoids, juvenile hormone-like compounds, juvenile hormone mimics) compounds as antifouling agents in e.g. paint compositions for ships and immersed structures including oil drilling rigs and fish nets and novel juvenile hormone compounds. The compounds are active against barnacles including species of <i>Cirripedia</i> such as <i>Balanus</i> species and prevent crucial steps in the process of barnacle fouling on solid surfaces such as the settlement, attachment and/or metamorphosis of barnacle cyprid larvae.

Description

NOVEL JUVENILE HORMONE ANALOGUES AND THEIR USE AS ANTIFOULING AGENTS

FIELD OF INVENTION

The present invention relates to the field of preventing or reducing fouling of surfaces of structures that are intermittently or continuously immersed in water. More specifically, there is provided novel juvenile hormone compounds that are effective in respect of inhibiting the settlement, attachment and/or metamorphosis of crustacean larval stages, in particular cy- prid larvae of barnacles and Cirripedia species. Juvenile hormone analogues having this biological activity can be used in antifouling compositions.

PRIOR ART AND TECHNICAL BACKGROUND

Numerous species of marine organisms, such as algae, tubeworms, ascidians, bryozoans, hydroids, barnacles and mussels live in both fresh water and saline water bodies. When a structure such as a ship, a boat, a fishing net, a drainage pipe or an off-shore oil drilling rig is placed in or on the water, marine organisms become attached to the structure and grow to give various kinds of damage to the structure. This phenomenon is generally referred to as fouling or bio-fouling. For example, if a ship's hull or the outer surfaces of any other type of vessel or structure that moves in the water is incrusted with marine organisms, the fric- tional resistance of the water increases and reduces the cruising performance of the vessel which in turn results in an increased fuel consumption. Also, the fouling of stationary immersed structures causes economic losses due to corrosion of the structures.

In order to solve the fouling problem several antifouling paint technologies have been developed. Currently, most antifouling paints contain biocides directed against one or more of the antifouling organisms. The majority of antifouling paints currently in use are effective because toxic components based on heavy metals are included in their formulation. In use, these heavy metals are leached out at various rates and concentrations from the matrix of the paint. However, the steady accumulation of these metals in the marine environment has adversely affected marine life, and restrictions have been or are being applied to their use. Examples of such antifouling components include cuprous oxide and triphenyl- or

CONFIRMATION CϋfY tributyltin. Several organic compounds have also been suggested and/or used as antifouling agents such as heterocyclic nitrogen compounds such as 3a,4,7,7a-tetrahydro-2- ((trichloromethyl)-thio)-1 H-isoindole-1 ,3(2H)-dione, pyridine-triphenylborane, 1 -(2,4,6- trichlorophenyl)-1 H-pyrrole-2,5-dione, 2,3,5,6-tetrachloro-4-(methylsulphonyl)-pyridine, 2- methylthio-4-tert-butylamino-6-cyclopropylamine-s-triazin, and quinoline derivatives; heterocyclic sulphur compounds such as 2-(4-thiazolyl)benzimidazole, 4,5-dichloro-2-octyl- 3(2H)-isothiazolone, 4,5-dichloro-2-octyl-3(2H)-isothiazoline, 1 ,2-benzisothiazolin-3-one, and 2-(thiocyanatomethylthio)-benzothiazole; urea derivatives; amides or imides of carbox- ylic acids; sulphonic acids and of sulphenic acids; salts or esters of carboxylic acids; amines such as dehydroabiethylamines and cocodimethylamine; substituted benzene such as 2,4,5,6-tetrachloro-1 ,3-benzenedicarbonitrile, 1 , 1 -dichloro-N-((dimethylamino)- sulphonyl)-1 -fluoro-N-phenylmethanesulphenamide, and 1 -((diiodomethyl)sulphonyl)-4- methyl-benzene; tetraalkyl phosphonium halogenides; and guanidine derivatives.

An important group of marine organisms that contributes significantly to the fouling process is the group of crustacean organisms that are collectively referred to as barnacles. These organisms belong to the Cirripedia subclass of the order Crustacea.

Adult barnacles are attached to solid surfaces, such as the underwater surfaces of vessels, by means of a proteinuous glue, secreted by a cement gland. They reproduce through the release of free-swimming nauplius larvae which develop through six stages into the cyprid larval stage. The cyprid settles on a solid surface and attaches itself by the release of a proteinuous cement, secreted from a cement gland. It then metamorphoses into a juvenile barnacle.

The Cirripedia subclass includes four orders: Thoracica, Acrothoracica, Ascothorica and Rhizocephala. Of these, species of Thoracica that belong to the genus Balanus, also referred to as acorn shell or rock barnacles, are commonly involved in fouling of submersed surfaces.

The metamorphosis of arthropods (insect and crustacean species) is controlled by several hormones. In insects, such hormones include molting hormones (MHs), also referred to as ecdysones, and juvenile hormones (JHs), the latter class of compounds being terpenoid compounds. Together with the molting hormones circulating in the bloodstream of the in- sects, the juvenile hormones play vital roles in growth, development and reproduction of insects. If insects are treated with an excess of the juvenile hormone at an early stage in their development, their life cycle is distorted, and they will remain in a juvenile (larval) stage and not develop into the adult insect. Whereas natural JHs have not been used commercially as insect controlling compounds, several juvenile hormone analogues, also referred to herein as juvenile hormone-like compounds, juvenoids or juvenile hormone mimics, are currently used as insect controlling compounds.

The natural juvenile hormones (JHs) are a class of compounds that regulate both metamorphosis and gametogenesis in insects.¹ Five compounds have been isolated and cha- racterized.² They can all be considered as derivatives of methyl 10,11 -epoxyfarnesoate and appear to be universally distributed among insects. Despite their potential as natural insecticides there has been no widespread use of the JHs as such. This is due in part to the facile hydrolysis of the epoxide ring to the biologically inactive diols but also to the lack of species specificity. One approach to overcome these problems is to use structurally dif- ferent compounds with JH activity, so-called juvenile hormone analogues (JHAs) or juvenoids. A large number of juvenoids have been prepared and tested resulting in many highly active insect controlling compounds.³ The large structural variation of these compounds combined with the species specificity often exhibited makes it difficult to predict whether a class of compounds will be active towards a particular insect species. Much more informa- tion is needed before a workable structure-activity relationship can be established. The most general conclusion that can be drawn based on the present knowledge is that the juvenoids should be lipophilic with a terminal polar group.⁴

Several authors have speculated on the presence of JHs in other arthropods, but the only detection reported is that of a JH-like compound in a crustacean species.⁵ A few reports have indicated that juvenile hormone analogues may have biological effects on barnacles.^{6" 9} One example is the effect of the commercial insect growth regulator ZR-512/Altozar (methoprene; isopropyl 3,7,11-trimethyldodeca-2,4-dienoate) that has been found to cause precocious metamorphosis of the cyprid larvae of the acorn barnacle, Balanus galeatus, at a concentration of about 30 ppb⁷. An ethyl derivative of that compound caused a total metamorphosing effect on the same barnacle species at a concentration of 100 ppb and an exposure time of 3 h whereas an isopropyl derivative of ZR-512/Altozar did not have an effect on the metamorphosis of Balanus galeatus.⁶ However, during the experimentation leading to the present invention it was found the ZR- 512/Altozar was practically inactive against three other Balanus species, namely β. bala- noides, B. improvisus and B. amphitrite.

It is thus known that at least certain juvenile hormone analogues have an effect on the metamorphosis of Balanus galeatus. No reports seem to suggest an effect of juvenile hormone analogues on the metamorphosis of other Balanus species including the important fouling organisms B. balanoides, B. amphitrite and β. improvisus.

If juvenile hormone analogues that affect a broad range of fouling barnacles at low concentrations were available, such compounds would be commercially interesting candidates for antifouling agents in antifouling compositions including paints.

The present invention has now provided a large range of novel, structurally diverse juvenile hormone analogues, of which many, even at very low concentrations such as < 100 ppb or even < 10 ppb affect the metamorphosis of barnacle larvae and it has been found that a substantial number of such compounds can prevent that cyprid larvae of barnacles settle on solid surfaces. This opens up for a systematic approach for developing and selecting non-toxic antifouling agents that are selectively controlling the fouling by barnacles.

SUMMARY OF THE INVENTION

In a first aspect, the invention relates to a juvenile hormone analogue (juvenoid) compound selected from the group consisting of

(i) a compound of the general formula I

where R is alkyl or branched alkyl including alkenyl, alkadienyl and alkatrienyl, optionally substituted isoprenoid or alkoxy substituted alkyl, R² is hydrogen or alkyl, X is oxygen, sul- fur, methylene, carbinol or carbonyl, Y is nitrogen or methinine and Z is nitrogen, methine or nitrogen oxide;

(ii) a compound of general formula II

where R¹ is 2,2-dimethylcyclopropyl, 2,2-dihalo-3,3-dimethylcyclopropyl, 2-methyl-1- propenyl or 3-methyl-1 ,2-butadienyl, R² is hydrogen or methoxy, R³ is alkyl, alkenyl, acetyl, formyl or carbomethoxy, R⁴ is hydrogen or R³ and R⁴ together is methylenedioxy and X is oxygen or sulfur;

(iii) a compound of the general formula III

where R¹ is 2-methylbutyl, 2,2-dimethylcyclopropyl or 2,2-dihalo-3,3-dimethylcyclopropyl and R² is methyl, ethyl or isopropyl,

(iv) a compound of the general formula IV

where X is oxygen or sulfur and Ar is a heteroaromatic group, and (v) a compound selected from the group consisting of

55: 4-Octylmorpholine;

56: 1-Octylpiperidine;

58: 1 ,4-Dioctylpiperazine;

59: 3-(3',7'-Dimethyloctyloxy)pyridine;

60: 3-(3',7'-Dimethyloctylsulfanyl)pyridine;

1-205: 3,3-dimethylocta-2,6-dienoic acid dimethylamide; and

1-265: 3,3-dimethyl-3-oxaundecanoic acid dimethylamide

subject to the limitation that the compound is not 5-(3',7'-Dimethylocta-2',6'-dienyloxy)-2- methylpyridine, 3-(3',7^,-Dimethylocta-2',6'-dienyloxy)pyridine, 5-(3',7'-Dimethylocta-2',6'- dienylsulfanyl)benzo[1 ,3]dioxole or Methyl 7,11-dimethyl-dodeca-2,4-dienoate.

In a further aspect there is provided a juvenile hormone analogue compound that, at a concentration of at the most 10 ppm, inhibits the settlement and/or attachment of cyprid larvae of a Cirripedia species onto a solid surface in contact with an aqueous medium containing said concentration of the compound and/or the metamorphosis of such larvae in the aqueous medium, by at least 50% (EC-50), relative to cyprid larvae contained in a medium not containing the compound.

In still further aspects, the invention relates to a method of controlling the fouling of a surface with a living organism, the method comprising applying to said surface an effective amount of a juvenile hormone analogue compound including any of the above compounds, an antifouling composition comprising a juvenile hormone compound as defined above, methods of preparing the novel compounds of the invention and the use of a juvenile hormone analogue as an antifouling agent in a paint composition.

DETAILED DISCLOSURE OF THE INVENTION

It is a major objective of the invention to provide novel juvenile hormone compounds as defined above which are structurally varied so as to provide compounds that are useful as antifouling agents. Useful classes of compounds according to the invention are compounds of the general formula I where R¹ is alkyl or branched alkyl including alkenyl, alkadienyl and alkatrienyl, optionally substituted isoprenoid or alkoxy substituted alkyl, R² is hydrogen or alkyl, X is oxygen, sulfur, methylene, carbinol or carbonyl, Y is nitrogen or methinine and Z is nitro- gen, methine or nitrogen oxide; compounds of the general formula II where R¹ is 2,2-dimethylcyclopropyl, 2,2-dihalo-3,3-dimethylcyclopropyl, 2-methyl-1-propenyl or 3-methyl- 1 ,2-butadienyl, R² is hydrogen or methoxy, R³ is alkyl, alkenyl, acetyl, formyl or carbomethoxy, R⁴ is hydrogen or R³ and R⁴ together is methylenedioxy and X is oxygen or sulfur; compounds of the general formula III and compounds of the general formula IV.

The term "alkyl" as used herein refers to a straight or branched chain saturated or unsatu- rated aliphatic group e.g. having one to eleven carbon atoms, such as methyl, propyl, isopropyl, n-butyl, t-butyl, pentyl, hexyl, heptyl or octyl.

It has been found that the structure of the juvenile hormone analogue has a significant effect on the biological activity against target organisms. In useful embodiments, the compound of the invention is a compound of the general formula I where R¹ is straight chain or branched alkyl or an alkoxyy substituted alkyl. In further useful embodiments, R in compounds of general formula I is isoprenoid including cyclopropyl substituted isoprenoid such as famesyl or R1 is α/em-dihalocyclopropyl substituted isoprenoid.

In useful compounds of the general formula I, X is oxygen or sulfur. Particularly useful compounds of the invention include compounds of the general formula I where Y and/or Z is nitrogen.

Specific compounds according to the invention include compounds of the general formula I selected from the group consisting of

1 : 5-(7'-Ethoxy-3',7'-dimethyloctyloxy)-2-methylpyridine; 2: 5-(3',7'-Dimethyloctyloxy)-2-methylpyridine;

R-2: (3' )-5-(3',7'-Dimethyloctyloxy)-2-methylpyridine;

S-2: (3'S)-5-(3',7'-Dimethyloctyloxy)-2-methylpyridine;

3: 2-Methyl-5-(7'-methyloctyloxy)pyridine;

4: 2-Methyl-5-octyloxypyridine; 5: 5-(3',7'-Dimethyloct-6'-enyloxy)-2-methylpyridine; 6: 5-(3\7'-Dimethylocta-2\6'-dienyloxy)-2-methylpyridine;

7: 3-(3',7'-Dimethylocta-2',6'-dienyloxy)pyridine;

8: 5-[5'-(2",2"-Dichloro-3",3'^,-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2-ethylpyridine;

9: 5-[5^,-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2^*-enyloxy]-2- 5 methylpyridine;

10: 5-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2-ethylpyridine;

11 : 5-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2-methylpyridine;

12: 5-[5'-(2^M,2"-Dimethylcyclopropyl)-3'-methylpentyloxy]-2-methylpyridine;

13: 5-(3\7'-Dimethyloctylsulfanyl)-2-methylpyridine; 10 14: 2-(3',7'-Dimethylocta-2',6'-dienyloxy)pyridine;

15: 2-(3',7'-Dimethyloctylsulfanyl)pyridine;

16: 3-(3',7'-Dimethyloctyloxy)-1 -methylpiperidine;

46: 2-Methyl-5-nonyloxypyridine;

47: 2-Methyl-5-undecyloxypyridine; 15 48: 5-Dodecyloxy-2-methylpyridine;

49: 2-Methyl-5-(3',7', 11 '-trimethyldodeca^'.e', 10'-trienyloxy)pyridine;

51 : 3-(4',8'-Dimethylnonyl)pyridine;

52: 3-(4',8'-Dimethylnonyl)pyridine-N-oxide;

53: 4,8-Dimethyl-1-pyridin-3-ylnonan-1-ol; 20 54: 4,8-Dimethyl-1-pyridin-3-ylnonan-1-one;

59: 3-(3',7'-Dimethyloctyloxy)pyridine;

60: 3-(3',7^,-Dimethyloctylsulfanyl)pyridine;

61 : 3-(7'-Ethoxy-3^,,7'-dimethyloctyloxy)pyridine;

F-1 : 3-[2'-(4"-Phenoxyphenoxy)ethoxy]pyridine; 25 F-3: 2-[2'-(4"-Phenoxyphenoxy)ethoxy]pyridine; and

F-4: 3-(4'-Phenoxybenzyloxy)pyridine.

I-230: 2-methyl-5-decyloxypyridine

Further useful compounds of the invention include compounds of the general formula II in- 30 eluding such compounds having saturated side chains to the aromatic ring and compounds of the general formula II where R³ and R⁴ together is methylenedioxy and such compounds where X is oxygen.

Specific compounds of the general formula II include compounds selected from the group 35 consisting of 17: 5-(3',7'-Dimethyloctyloxy)benzo[1 ,3]dioxole;

18: 5-(3',7^,-Dimethylocta-2',6'-dienyloxy)benzo[1,3]dioxole;

19: 5-[5'-(2",2"-Dimethylcyclopropyl)-3^,-methylpent-2'-enyloxy]benzo[1 ,3]dioxole; 5 20: 5-[5^,-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- enyloxy]benzo[1 ,3]dioxole;

21 : 5-[5'-(2",2"-Dibromo-3",3^,,-dimethylcyclopropyl)-3'-methylpent-2'- enyloxy]benzo[1 ,3]dioxole;

22: 5-(3',8'-Dimethylnona-2^,,6',7^,-trienyloxy)benzo[1 ,3]dioxole; 10 24: 1 -[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-4-ethylbenzene;

25: 1-[5'-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-4- ethylbenzene;

26: 1-[5'-(2",2"-Dibromo-3",3^,,-dimethylcyclopropyl)-3^,-methylpent-2'-enyloxy]-4- ethylbenzene; 15 27: 1 -(3\8'-Dimethylnona-2\6\7'-trienyloxy)-4-ethylbenzene;

28: Methyl 4-[5'-(2",2"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]benzoate;

29: Methyl 4-[5'-(2",2"-dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- enyloxyjbenzoate;

30: Methyl 4-[5'-(2",2"-dibromo-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- 20 enyloxy]benzoate;

31 : 1 -Acetyl-4-[5'-(2",2"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]benzene;

32: 1-Acetyl-4-[5^,-(2",2"-dichloro-3",3"-dimethylcyclopropyl)-3^,-methylpent-2'- enyloxyjbenzene;

33: 1-Acetyl-4-[5'-(2",2"-dibromo-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- 25 enyloxyjbenzene;

34: (3,7-Dimethyloctyloxy)benzene;

35: 4-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-3-methoxybenzaldehyde;

36: 4-[5^,-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2^,-enyloxy]-3- methoxybenzaldehyde; 30 37: 1-[5'-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2-methoxy-4- propenylbenzene; and

38: 4-Allyl-1-[5^,-(2^,,,2"-dichloro-3",3"-dimethylcyclopropyl)-3^,-methylpent-2'-enyloxy]-2- methoxybenzene. Further specific compounds according to the invention include compounds of the general formula III selected from the group consisting of

40: Methyl 9-(2^',2^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate 41 : Ethyl 9-(2^',2^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate 42: Isopropyl 9-(2^',2^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate 43: Methyl 9-(2^',2^'-dichloro-3^'3^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate 44: Ethyl 9-(2^',2^'-dichloro-3^'3^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate 45: Isopropyl 9-(2^',2^'-dichloro-3^'3^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate

compounds of the general formula IV selected from the group consisting of

50: 5-(3',7'-Dimethyloctyloxy)-2-methylpyrimidine, and 57: 2-(3',7^,-Dimethyloctylsulfanyl)thiophene,

and the compounds

55: 4-Octylmorpholine; 56: 1-Octylpiperidine; 58: 1 ,4-Dioctylpiperazine;

59: 3-(3',7'-Dimethyloctyloxy)pyridine;

60: 3-(3',7'-Dimethyloctylsulfanyl)pyridine;

I-205: 3,3-dimethylocta-2,6-dienoic acid dimethylamide; and

I-265: 3,3-dimethyl-3-oxaundecanoic acid dimethylamide

In a further aspect of the invention juvenile hormone analogues are provided that, at a concentration of at the most 10 ppm, inhibit the settlement and/or attachment of cyprid larvae of the Cirripedia species Balanus balanoides, Balanus improvisus or Balanus amphitrite onto a solid surface in contact with an aqueous medium containing said concentration of the compound and/or the metamorphosis of such larvae in the aqueous medium, by 50% (EC-50), relative to such cyprid larvae contained in a medium not containing the compound. The EC-50 values for any of these Balanus species is determined in accordance with the specific settlement test procedures described for each species in the following Example 2. It is conceivable that this high biological activity against Balanus balanoides, Balanus improvisus and Balanus amphitrite that is observed with compounds of the invention is due to inhibition of the metamorphosis from the cyprid larval stage to the adult, sessile stage. The biological effect may also be directed against the settling capacity of the barnacles such as an abnormal development of the organs whereby the organisms attach to solid surfaces.

It will be appreciated that in order to evaluate whether a juvenile hormone analogue candidate has the required biological activity, standard test systems for determining juvenile hormone activity can be applied. Accordingly, encompassed within the meaning of juvenile hormone analogue compounds having "juvenile hormone activity" are compounds which prove to be positive when tested in a standard test system for evaluating compounds for juvenile hormone activity. Such standard tests, wherein Tenibrio molitor typically is applied as test organism, are well known in the art (se e.g. Slama et al., Insect Hormones and Bio- analogues, Springer-Verlag, New York 1974, p. 93). Additionally, the below evaluation system for determining juvenile hormone activity can be applied (adapted from "Methods used to evaluate candidate materials for juvenile hormone activity", Pesticide Chemicals Research Branch, Beltsville, Maryland):

Juvenile hormone activity may be determined using newly-molted (4-8 hours) Tenibrio mo- litor pupae. The compounds to be evaluated are formulated to contain 10 μg in 1 ml of solution. Acetone is a preferred solvent and is used in both topical and vapor tests. Topical application is with a micro applicator (Isco model M) fitted with a tuberculin syringe and a 27 gauge needle. One μl of the desired solution is administered/pupa on the venter of the last three abdominal segments. Vapor action is determined by applying the candidate compound to the lower 1/3 of a 1 pint freezer type jar and then inverting the jar into a 1/2 pint container, containing 5 pupae. A dosage of 1 μl of the desired solution per pupa (5 μl/jar) is used. All pupae are held until the following molt to determine juvenile hormone activity, which is indicated by the presence of immature characters; e.g. i) retention of gin traps, ii) retention of gin traps and urogomphi, iii) retention of gin traps and urogomphi plus retention of pupal cuticle around area of treatment, and iv) 2nd pupae - retention of all pupal characters. If a perfect adult is obtained after molting, the compound has no juvenile hormone activity. Farnesyl methyl ether is used as the standard for both topical and vapor tests. As it is demonstrated in the following examples, the structure of the compounds according to the invention has a significant effect on their biological activity. Thus, it was shown that among the compounds tested pyridyl ethers in general had the highest biological activity in the below test system. Specifically it was shown that such compounds where the ether lin- kage is attached to the pyridine ring at the 3-position are more active than corresponding compounds having the ether linkage attached to the 2-position. It was also found for these pyridyl ether compounds that when the substituent in the 6-position of the pyridine ring is changed from ethyl to methyl to hydrogen the activity decreases in that order. Replacing the oxygen in pyridyl ether compounds with sulfur resulted in compounds that were practi- cally inactive in the test system described in the examples below.

With respect to phenolic ethers according to the invention it was found that comparable structural variations as those observed for the pyridyl ethers have similar effects on their antifouling activity.

It is generally assumed that for obtaining high activity of a juvenile hormone analogue, the molecule should have a polarity that is sufficient for optimum solubility in the cytoplasm of cells of the target organisms as well as a lipophilic character that enables penetration of the cuticle of the target organism. Accordingly, it is believed that the most active compounds of the invention are those having an appropriate balance between hydrophobicity and lipophi- licity.

In preferred embodiments, the juvenile hormone analogue is a compound that in a settlement test as described hereinbelow using Balanus balanoides, Balanus improvisus or Balanus amphitrite as the test organisms has an EC-50 of at the most 10 ppm such as at the most 1 ppm including at the most 100 ppb e.g. 80 ppb such as at the most 60 ppb including at the most 50 ppb such as at the most 30 ppb including at the most 20 ppb, such as at the most 10 ppb or even at the most 1 ppb.

It is a further objective of the invention to provide a method of controlling the fouling of a surface with a living organism, the method comprising applying to said surface an effective amount of a juvenile hormone analogue compound. In the present context, the expression "applying to said surface" includes embodiments where the juvenile hormone analogue is dissolved or suspended in water. In preferred embodiments, the juvenile hormone ana- logue compound used in such a method is a compound according to the invention as de- fined above. The target organisms in the method is any arthropod species that causes fouling of submersed vessels and other structures such as e.g. oil drilling rigs and fishing nets that are occasionally or permanently immersed in fresh water or saline water. Such target species include larval stages of fouling crustacean species, in particular barnacle species of the Cirripedia subclass including Balanus galeatus, Balanus amphitrite, Elminius modestus, Balanus improvisus, Balanus balanoides and Balanus crenatus.

Preferably, the juvenile hormone analogue is applied to the surface to be protected from fouling by incorporating the compound into a coating composition such as a paint composi- tion including paints for ships and immersed stationary structures such as e.g. fishing nets or oil drilling rigs. In accordance with the invention, such compositions can be prepared according to conventional manufacturing technology and the compositions may, in addition to the juvenile hormone analogue, contain components that are usual for paint compositions including binders, pigments, extenders, additives and solvents (e.g. as previously de- scribed in US 5,332,430).

The amount of juvenile hormone analogue in such compositions is generally in the range of 0.1-50% by weight of the composition, such as in the range of 0.5-25%, including the range of 1-20%, such as in the range of 1.5-15% by weight of the composition. In one embodi- ment the amount of juvenile hormone analogue is in the range of 2-10% by weight of the composition.

Examples of suitable binders for such coating composition, including paint compositions, include functionalised acrylates (like methacrylates, metal acrylates and silyl acrylates), vinyls (like copolymer of vinyl chloride and vinyl isobutyl ether), chlorinated rubbers and rosins (like gum rosin, wood rosin and tall oil rosin). Examples of pigments include titanium dioxide, zinc oxide, carbon black, iron oxide and colour pigments. Examples of extenders/fillers include sulfates, oxides, silicates and carbonates. Examples of additives include thixotropic agents (like bentonite and aerosil), plasticizers (like chlorinated paraffins, tri cresyl phosphate, phtalates and polyvinyl ethyl ether). Examples of solvents include aliphatic and aromatic hydrocarbons (like heptane and xylene), alcohols (like butanol), ke- tones (like methyl isobutyl ketone), esters (like ethyl acetate and butyl acetate), water and others (like 1-metoxy-2-propanol), and mixtures of these. It will be appreciated that a coating composition according to the invention may contain two or more different juvenile hormone analogues to obtain a broad range activity against a variety of barnacle species and other fouling arthropod organisms that are susceptible to juvenile hormone analogues.

Additionally, the antifouling coating composition may contain at least one further biocidally active compound including any of the currently used antifouling agents including algicides. Examples of such biocidally active compounds includes copper metal, cuprous oxide, cuprous thiocyanate, bis (2-pyridinethiol 1 -oxide) zinc, bis (2-pyridinethiol 1 -oxide) copper, 4,5-dichloro-2-octyl-3(2H)-isothiazolinone, 2-methylthio-4-tert-butylamino-6- cyclopropylamino-triazine, zinc ethylenebis (dithiocarbamate) and pyridine triphenylborane.

The antifouling composition of the invention may contain any juvenile hormone analogue that is effective against one or more fouling arthropod organisms, including any of the novel compounds according to the invention. In one preferred embodiment, the antifouling composition of the invention comprises a juvenile hormone analogue of the general formula I where Z is nitrogen.

It is also an objective of the invention to provide methods for synthesising the novel com- pounds of the invention. Detailed descriptions of their synthesis are given in the examples below.

The invention will now be described in further details in the following, non-limiting examples.

EXAMPLE 1

Syntheses of juvenile hormone analogue compounds

1.1 Materials and Methods

General. The instruments employed have been described elsewhere.¹⁰ IR spectra were obtained on neat films and the NMR spectra were recorded relative to TMS in CCI₄ unless stated otherwise.

Compounds. Most of the starting materials were commercially available. 1-Bromo-7- ethoxy-3,7-dimethyloctane,¹¹ 1-bromo-3,7-dimethyl-2,6-octadiene,¹² 2-(4-chlorobutoxy) tet- rahydropyran,¹³ 1-bromo-3,7-dimethyloctane,¹ 1-bromo-3,7-dimethyl-6-octene,¹⁴ 5-(2,2- dichloro-3,3-dimethylcyclopropyl)-3-methyl-1-penten-3-ol (65b),¹⁵ 5-(2,2-dibromo-3,3- dimethylcyclopropyl)-3-methyl-1-penten-3-ol (65c),¹⁵ 3-pyridinethiol,¹⁶ 2-thiophenethiol²² and famesyl bromide¹⁷ were prepared according to literature methods.

1.2. Preparation of compounds

The reactions which lead to the (cyclopropyl)alkyl aromatic ethers are depicted in Scheme 1 below. The ester 39 was prepared according to the literature. The esters 40-45 were prepared by the reactions shown in the below Scheme 2. The final steps are essentially those used by Henrick et al. for the preparation of Altosid.¹⁸

Aromatic and heteroaromatic ethers and thioethers. General. The heteroaromatic ethers and thioethers 1-15, the phenyl ethers 17-38, and the piperidyl ether 16 were all prepared by the same general procedure used for the preparation of compound 2 ( see below). The preparation of some of the halides are given below.

2-(3', 7'-Dimethyloctylsulfanyl)thiophene (57) was obtained using the general procedure by Fedorov and Stoyanovich²⁸ starting from 1.93 g (23 mmol) thiopene, 16 mL (24 mmol) 1.53 M BuLi in hexane, 0.74 g (23 mmol) sulphur and 5.00 g (23 mmol) 1-bromo-3,7- dimethyloctane in 5 mL ether and 15 mL dry DMF. Short path distillation (bath 98°C/0.02 mmHg) yielded 3.1 g (53%) of 57. 4,8-Dimethyl-1-pyridin-3-ylnonan-1-one (54) was prepared according to Frank and Weater- bec's procedure²³ starting with 22.1 g (0.10 mol) of 1-bromo-3,7-dimethyloctane, 2.7 g (0.11 mol) Mg and 9.4 g (0.09 mol) 3-cyanopyridine in 150 mL dry ether. Extraction with dichloromethane, drying (MgSO₄), evaporation and short path distillation (bath 109-114 °C/0.02 mmHg) gave 9.4 g (42%) of 54.

3-(4',8'-Dimethylnonyl)pyridine (51). A mixture of 2.0 g (8 mmol) of 54, 1.0 g (16 mmol) KOH (85%) in 15 mL trimethyleneglycol was heated to 180-190°C for 5 h, cooled to room temperature overnight and diluted with 100 mL water and 25 mL brine. Extraction with di- chloromethane, washing of the combined organic extracts with brine, drying (K₂CO₃) and evaporation followed by distillation (bp. 70-72°C/0.02 mmHg) yielded 1.41 g (74%) of 51.

3-(4',8'-Dimethylnonyl)pyridine-N-oxide (52). Using the procedure of Taylor and Corvetti²⁵ for the oxidation of alkylpyridines, 0.93 g (4.0 mmol) 51 in 0.7 mL (6 mmol) 30% H₂O₂, 1.3 mL acetic acid and 1.1 mL 40% NaOH(aq) gave 0.80 (80%) of 52.

4, 8-Dimethyl-1-pyridin-3-ylnonan-1-ol. (53). Reduction of 3.00 g (12.1 mmol) 54 with 0.20 g (5.0 mmol) LiAIH in 50 mL ether followed by usual work up and short path distillation (bath 120°C/0.01 mmHg) gave 1.2 g (40%) 53.

The yields varied from 40-90 % and were not optimised.

m Scheme 2

iv), v) iv) - viii)

vi)

viii)

i) H7HC(OEt)₃ ii) CHX3/50% NaOH/CH₂CI₂ iii) Na/NH₃ (l)/-78°C iv) H7H₂O v) MeO₂CCH=C(Me)CH₂CO₂Me/NaOH vi) 2,4-dimethylpyridine/D vii) a) PhSH/D b) NH₃ viii) a) SOCI₂/DMF b) ROH 5-(3', 7'-Dimethyloctyloxy)-2-methylpyridine (2). To a stirred solution of 10 ml 2M NaOMe (20 mmol) in MeOH was added 2.18 g (20 mmol) of 3-hydroxy-6-methylpyridine. After stirring at room temperature for 15 min., MeOH was evaporated under vacuum. The sodium salt was dissolved in dry DMF and 4.42 g (20 mmol) of 1-bromo-3,7- dimethyloctane was added. The mixture was stirred at room temperature for 16 h and then diluted with diethyl ether (200 ml) to precipitate NaBr. The organic layer was separated and washed successively with 10% aq. NaOH and water and dried (MgSO₄).

Evaporation and short path distillation (131°C / 0.02 mmHg) gave 4.39 g (88%) of the ether 2.

The allenes 22 and 27 were prepared from the corresponding dibromocyclopropanes 21 and 26, respectively, by reactions with methyllithium at -78°C.¹⁹

7-Methyl-1-octanol (63) was made according to the procedure by Tamura and Kochi.²⁰ A solution of 19.3 g (0.10 mol) 2-(4-chlorobutoxy) tetrahydropyran in dry THF (75 ml ) was added dropwise to 2.6 g (0.11 mol) Mg in dry THF (75 ml ) activated with 0.5 ml ethyl bromide. After cooling in ice, 18.1 g (0.12 mol) of 1-bromo-3-methylbutane was added, followed by Li₂CuCI₄ (4 ml; 0.1 M in THF). The mixture was stirred for 3 h. at 0°C and overnight at room temperature. The reaction was quenched by the addition of water (25 ml). Extraction with ether, drying (MgSO₄) and distillation gave 15.7 g (69%) of 2-(7- methyloctyl)tetrahydropyran. The compound was hydrolysed with an aqueous-ethanolic solution of HCI at room temperature in the usual way. Distillation of the crude product gave 7.5 g (75%) of the alcohol 63, b.p. 98-102°C/11 mmHg. IR : 3300 (s), 1385 (m), 1365 (m) cm . ¹H NMR: δ 0.87 (d, =6 Hz, 2H), 1.2-1.7 (m, 11 H), 3.30 (s, 1 H), 3.50 (t, J =6 Hz, 2H).

1-Bromo-7-methyloctane (64). A solution of 14.4 g (55 mmol) Ph₃P in diethyl ether (-100 ml) was added to a stirred solution of 7.4 g (51 mmol) of alcohol 63 and 18.2 g (55 mmol) of CBr₄ in diethyl ether(100 ml). The mixture was stirred at room temperature for 48 h. and filtered. The residue was washed with ether. The combined ether solution was evaporated and the residue extracted with pentane. The dried (CaCI₂) extract was distilled to give 6.4 g (60%) of the bromide 64, b.p. 85-88 °C/ 9 mmHg. ¹H NMR: δ 0.85 (d, J =5.5 Hz, 6H), 1.1-2.0 (m, 11 H), 3.32 (t, J =6 Hz, 2H). 5-(2,2-Dimethylcyclopropyl)-3-methyl-1-penten-3-ol (65a). A solution of 11.9 g (50 mmol) of the alcohol 65b¹⁵ in diethyl ether (35 ml) was added to a stirred solution of 5.0 g (217 mmol) Na in NH₃(I) (125 ml) in small portions until the mixture turned white. Ammonia was evaporated, the residue extracted with ether and dried (MgSO₄). Evaporation of the sol- vent gave 8.3 g (98%) of the alcohol 65a, sufficiently pure for use in further reactions. IR :

3400(s) cm . ¹H NMR: δ -0.15 (bs, 1 H), 0.37 (bs, 2H), 1.04 (s, 6H), 1.23 (s, 3H), 1.3-1.6 (m, 4H), 1.67 (bs, 1 H), 4.9-6.2 (m, 3H).

1-Bromo-5-(2,2-dimethylcyclopropyl)-3-methyl-2-pentene (66a) To 8.4 g (50 mmol) of al- cohol 65a, cooled in ice, was added 50 ml of 48% aq. HBr. The mixture was stirred at this temperature for 30 min. and then diluted with water. The product was extracted with CH₂CI₂; the extract was washed with saturated NaHCO₃ (aq.) and dried (MgSO₄). Evaporation and short path distillation of the residue gave 11.1 g (96 %) of the bromide 66a, IR:

1655(m) cm^"1. Η NMR: δ -0.12 (bs, 1 H), 0.40 (bs, 2H), 1.03 (s, 6H), 1.73 (bs, 3H), 1.2-2.3 (m, 4H), 3.95 (d, J =8.5 Hz, 2H), 5.53 (bt, J =8.5 Hz, 1H).

1-Bromo-5-(2,2-dichloro-3,3-dimethylcyclopropyl)-3-methyl-2-pentene (66b) was prepared in 92% yield by the procedure described for 66a, b.p. 98°C /10^-3 mmHg. IR: 1660(m),

825(s) cm . ¹H NMR: δ1.16 (s, 3H), 1.35 (s, 3H), 1.77 (bs, 3H), 1.1-2.4 (m, 5H), 3.93 (d, J =8.5 Hz, 2H), 5.55 (bt, J =8.5 Hz, 1H).

1-Bromo-5-(2,2-dibromo-3,3-dimethylcyclopropyl)-3-methyl-2-pentene (66c) was prepared in 85% yield by the procedure described for 66a. IR: 1650(m) , 760(s) cm . ¹H NMR: δ1.18 (s, 3H), 1.38 (s, 3H), 1.77 (bs, 3H), 1.1-2.4 (m, 5H), 3.93 (d, =8.5 Hz, 2H), 5.55 (bt, J =8.5 Hz, 1H).

5-(2,2-Dichloro-3,3-dimethylcyclopropyl)-3-methyl-1-pentanol (68b). Citronellol tetrahy- dropyranyl ether (67) was prepared in the usual way in 91% yield. To an ice-cooled and stirred mixture of 17.8 g (74 mmol) of 67, 12.0 g (100 mmol) of CHCI₃ and 0.2 g triethyl- benzylammonium chloride in CH₂CI₂ (50 ml) was added dropwise 50% aq. NaOH (50 ml). The mixture was stirred vigorously for 19 h at room temperature and then diluted with water (150 ml). The product was extracted with CH₂CI₂. The residue obtained after evaporation of solvent was dissolved in 100 ml ethanol and 100 ml 0.1 M HCI, and stirred at room temperature for 21 h. The product was extracted with CH₂CI₂. The extract was washed subsequently with saturated aq. NaHCO₃, brine and dried (MgSO ). Evaporation and distillation gave 12.3 g (69%) of the alcohol 68b, b.p. 146-148°C/9 mmHg. IR:

3300(s), 830(s) crτr¹. ¹ H NMR: δ 0.93 (d, J =5 Hz, 3H), 1.15 (s, 3H), 1.33 (s, 3H), 1.1 -1.9 (m, 8H), 3.58 (t, =5 Hz, 2H), 4.28 (bs, 1 H).

5-(2,2-Dimethylcyclopropyl)-3-methyl-1-pentanol (68a) was prepared in 58% yield by reduction of 68b using the same procedure as described for 65a, b.p. 109-110°C /10 mmHg. IR: 3300(s) cm-¹. ¹H NMR: δ -0.12 (bs, 1 H), 0.37 (bs, 2H), 0.88 (d, J =5 Hz, 3H),

1.02 (s, 6H) , 1.2-2.0 (m, 7H), 3.43 (bs, 1 H), 3.55 (t, =6.5 Hz, 2H).

1-Bromo-5-(2,2-Dimethylcyclopropyl)-3-methylpentane (69) was prepared in 66% yield from the alcohol 68a by the procedure used for the preparation of 64, b.p. 99-100°C /10 mmHg. IR: 800(s) cm . ¹H NMR: δ -0.13 (bs, 1 H), 0.38 (bs, 2H), 0.92 (d, J =5 Hz, 3H),

1.03 (s, 6H) , 1.1-1.9 (m, 7H), 3.36 (t, =7 Hz, 2H).

5-(2,2-Dichloro-3,3-dimethylcyclopropyl)-1, 1-diethoxy-3-methylpentane (70b) was prepared in 78% yield from citronellal diethyl acetal as described for compound 68b, b.p.

95°C/ 0.01 mmHg. IR: 825(s) cm . ¹H NMR: δ 0.93 (d, J =5.5 Hz, 3H), 1.13 (t, J =7 Hz, 6H), 1.16 (s, 3H), 1.34 (s, 3H), 1.2-1.7 (m, 8H), 3.48 (dq, J =7 Hz, 4H), 4.50 (bt, =5 Hz, 1 H).

5-(2,2-dimethylcyclopropyl)-1, 1-diethoxy-3-methylpentane (70a) was prepared in 90% yield by reduction of the acetal 70b as described for compound 65a. The crude product was sufficiently pure for use in the next step. H NMR: δ -0.16 (bs, 1 H), 0.33 (bs, 2H), 0.88 (d, =5.5 Hz, 3H), 1.00 (s, 9H), 1.12 (s, 3H), 1.23 (s, 3H), 1.2-1.7 (m, 4H), 3.45 (dq, J =7 Hz, 4H), 4.47 (bt, J =5 Hz, 1H).

5-(2,2-Dimethylcyclopropyl)-3-methylpentanal (71a) was prepared in 90% yield by hydrolysis of acetal 70a, b.p. 85-87°C/9 mmHg. IR: 1730(s) cm-¹. ¹H NMR: δ -0.10 (bs, 1 H), 0.43 (bs, 2H), 1.02 (d, J =6 Hz, 3H), 1.07 (s, 6H) , 1.3-1.5 (m, 5H), 2.2-2.4 (m, 2H), 9.75 (t, J =1.5 Hz, 1H).

5-(2,2-Dichloro-3,3-dimethylcyclopropyl)-3-methylpentanal (71b) was prepared in 90% yield by acid catalyzed hydrolysis of the acetal 70b, b.p. 81-82°C/0.05 mm Hg. IR: 1730(s), 840(s) cm^"1. ¹H NMR: δ 0.98 (d, =6.5Hz, 3H), 1.15 (s, 3H), 1.34 (s, 3H), 1.0-1.6 (m, 6H), 2.2-2.4 (m, 2H), 9.70 (t, J =1.5 Hz, 1 H).

9-(2,2- dimethylcyclopropyl)-3,7-dimethyl-2E,4E-nonadienoic acid (72a) was prepared in

18 33% overall yield from the aldehyde (71a) according to the literature procedure. IR:

3500(s), 1690(s), 1635(m), 1610(m) cm . ¹H NMR: δ -0.15 (bs, 1H), 0.38 (bs, 2H), 0.92 (d, J =5.5 Hz, 3H), 1.03 (s, 6H), 1.35 (s, 5H), 1.9-2.2 (m, 2H), 2.28 (s, 3H), 5.69 (bs, 1H), 6.12 (bs, 2H), 12.23 (s, 1 H).

9-(2, 2-dichloro-3, 3-dimethylcyclopropyl)-3, 7-dimethyl-2E, 4E-nonadienoic acid (72b) was prepared in 33% overall yield from the aldehyde(71 b) according to the literature procedure.¹⁸ IR: 3500(s), 1690(s), 1640(m), 1610(m) cm ¹H NMR: δ 0.90 (d, J =5 Hz, 3H), 1.15 (s, 3H), 1.2-1.6 (m, 6H), 2.0-2.2 (m, 2H), 2.28 (bs, 3H), 5.68 (bs, 1 H), 6.12 (bs, 2H), 11.92 (s, 1 H).

The acids 72 were converted in the usual way to the esters 40-45.

EXAMPLE 2

The biological activity of structurally different juvenile hormone analogues

The purpose of this study was to compare the biological activity of a number of structurally different juvenile hormone analogues on crustaceans. We selected three species of acorn barnacles, Balanus balanoides, Balanus improvisus and Balanus amphitrite, all of which cause fouling of ships and marine installations.

2.1 Materials and Methods

2.1.1 Juvenile hormone analogue compounds tested

In the below biological experiments, the following juvenile hormone analogue compounds were tested for their activity against one or more of the following barnacle (crustacean) species: Balanus balanoides, B. improvisus and B. amphitrite: 1 : 5-(7'-Ethoxy-3',7'-dimethyloctyloxy)-2-methylpyridine

2: 5-(3',7'-Dimethyloctyloxy)-2-methylpyridine

R-2: (3'f?)-5-(3',7'-Dimethyloctyloxy)-2-methylpyridine 5 S-2: (3'S)-5-(3',7'-Dimethyloctyloxy)-2-methylpyridine

3: 2-Methyl-5-(7'-methyloctyloxy)pyridine

4: 2-Methyl-5-octyloxypyridine

5: 5-(3',7'-Dimethyloct-6'-enyloxy)-2-methylpyridine

6: 5-(3',7'-Dimethylocta-2',6^,-dienyloxy)-2-methylpyridine 10 7: 3-(3',7'-Dimethylocta-2^,,6'-dienyloxy)pyridine

8: 5-[5^,-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2- ethylpyridine

9: 5-[5^,-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2- methylpyridine 15 10: 5-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2^,-enyloxy]-2-ethylpyridine

11 : 5-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2-methylpyridine

12: 5-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpentyloxy]-2-methylpyridine

13: 5-(3',7'-Dimethyloctylsulfanyl)-2-methylpyridine

14: 2-(3',7'-Dimethylocta-2^,,6'-dienyloxy)pyridine 20 15: 2-(3',7^,-Dimethyloctylsulfanyl)pyridine

16: 3-(3^,,7'-Dimethyloctyloxy)-1-methylpiperidine

19: 5-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]benzo[1 ,3]dioxole

20: 5-[5'-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3^,-methylpent-2'- enyloxy]benzo[1 ,3]dioxole 25 21 : δ-IS'-ζ ^^Dibromo-r.r-dimethylcyclopropy -S'-methylpent- - enyloxy]benzo[1 ,3]dioxole

22: 5-(3',8'-Dimethylnona-2',6',7^,-trienyloxy)benzo[1 ,3]dioxole

23: 5-(3',7'-Dimethylocta-2',6'-dienylsulfanyl)benzo[1 ,3]dioxole

24: 1-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-4-ethylbenzene 30 25: 1 -[5^,-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2^,-enyloxy]-4- ethylbenzene

26: 1-[5^,-(2",2"-Dibromo-3",3"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-4- ethylbenzene

27: 1-(3^*,8'-Dimethylnona-2',6',7'-trienyloxy)-4-ethylbenzene 35 28: Methyl 4-[5'-(2",2"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]benzoate 29: Methyl 4-[5'-(2",2"-dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- enyloxyjbenzoate

30: Methyl 4-[5'-(2",2"-dibromo-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- enyloxyjbenzoate 5 31 : 1-Acetyl-4-[5'-(2",2"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]benzene

32: 1-Acetyl-4-[5^,-(2"_I2^,,-dichloro-3^,,,3"-dimethylcyclopropyl)-3^,-methylpent-2^,- enyloxyjbenzene

33: 1-Acetyl-4-[5^,-(2",2"-dibromo-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- enyloxyjbenzene 10 34: (3,7-Dimethyloctyloxy)benzene

35: 4-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-3-methoxybenzaldehyde

36: 4-[5^,-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-3- methoxybenzaldehyde

37: 1-[5'-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3^,-methylpent-2'-enyloxy]-2-methoxy- 15 4-propenylbenzene

38: 4-Allyl-1-[5^,-(2",2"-dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2- methoxybenzene

39: Methyl 3,7,11-trimethyldodeca-2E,4E-dienoate

40: Methyl 9-(2^',2^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate 20 41 : Ethyl 9-(2^',2^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate

42: Isopropyl 9-(2',2^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate

43: Methyl 9-(2^',2^'-dichloro-3^'3^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate

44: Ethyl 9-(2^',2^'-dichloro-3^'3^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate

45: Isopropyl 9-(2^',2^'-dichloro-3^'3^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate 25 46: 2-Methyl-5-nonyloxypyridine

47: 2-Methyl-5-undecyloxypyridine

48: 5-Dodecyloxy-2-methylpyridine

49: 2-Methyl-5-(3',7', 11 '-trimethyldodeca-2',6', 10'-trienyloxy)pyridine

50: 5-(3',7'-Dimethyloctyloxy)-2-methylpyrimidine 30 51: 3-(4',8'-Dimethylnonyl)pyridine

52: 3-(4',8'-Dimethylnonyl)pyridine-N-oxide

53: 4,8-Dimethyl-1-pyridin-3-ylnonan-1-ol

54: 4,8-Dimethyl-1-pyridin-3-ylnonan-1-one

55: 4-Octylmorpholine 35 56: 1-Octylpiperidine 57: 2-(3',7'-Dimethyloctylsulfanyl)thiophene

58: 1 ,4-DioctyIpiperazine

61 : 3-(7'-Ethoxy-3',7^,-dimethyloctyloxy)pyridine

F-1 : 3-[2'-(4"-Phenoxyphenoxy)ethoxy]pyridine

F-3: 2-[2'-(4"-Phenoxyphenoxy)ethoxy]pyridine

F-4: 3-(4'-Phenoxybenzyloxy)pyridine

I-205: 3,3-dimethylocta-2,6-dienoic acid dimethylamide

I-230: 2-methyl-5-decyloxypyridine

I-265: 3,3-dimethyl-3-oxaundecanoic acid dimethylamide

All of these compounds with the exception of compounds 23 and 39 are novel compounds according to the invention.

2.1.2. Biological tests

The life cycle of acorn barnacles consists of six planktonic naupliar stages followed by a final larval stage, the cyprid, which after some time normally attaches itself to a substrate and undergoes metamorphosis into the sedentary adult form. Most species are hermaphrodites and after internal fertilization, the egg masses develop in two separate lamellae in the mantle cavity of the adults until the larvae are liberated as fully developed stage I nauplii. For the present study cultured cyprid larvae of three different barnacle species were used: two common marine and brackish water species of Western Europe and Eastern Atlantic North America (Balanus balanoides and B. improvisus), and one warm- water species with a global distribution (β. amphitrite).

Cultivation methods

Balanus balanoides and B. improvisus

In the laboratory, large numbers (usually about 35,000 to 50,000) of cyprids, were obtained by rearing larvae in 5-liter beakers through the six nauplii stages using the marine diatom Skeletonema costatum as food. The optimal temperature for rearing is 7.5°C for B. balanoides and 17.3°C for B. improvisus, in filtered natural sea water. Sodium benzyl- penicillinate (65 mg) and dihydrostreptomycin sulphate (135 mg) in 4.4 liters of medium were used as antibiotic. The batches of larvae were exposed to continuous indirect light- ing. The larvae of B. balanoides were transferred to a new beaker every day and every other day for those of B. improvisus by pouring the contents of the beaker through a 150 μm pore size nylon sieve. The retained larvae were then flushed into a new pre-treated beaker.

Balanus amphitrite

Adult brood stocks, maintained in plastic 10-liter carboys with aeration and controlled temperature (27°C) and light conditions (15 hours light/9 hours dark), were fed on a daily diet of Skeletonema costatum and naupliar larvae of the brine shrimp Artemia salina. Adults spontaneously released nauplii within 30 minutes to a few hours upon changing the water, removing the aeration and providing a concentrated light source. The photopositive larvae, collected by pipette and transferred to 8-liter carboys at a density of 1-2 larvae ml^"1, were fed daily with 500 ml Skeletonema costatum at 1-3χ10⁶ cells ml^"1. The carboys were kept at a temperature of 27°C and a 15/9h light/dark photo period. To prevent bacterial growth, a mixture of the antibiotics streptomycin and penicillin was added to the vessels at the start of the culture. When the majority (>75%) of the larvae had reached the cyprid stage (usually after 4-5 days), the culture was filtered through plankton sieves in order to separate the cyprids from the nauplii.

Cyprids were kept at 2-5°C in filtered seawater before settlement assays were carried out.

Settlement assay methods

The settlement assay compares the relative percent settlement of cyprids in control sea- water with settlement in serial dilutions of test compounds.

Balanus balanoides and B. improvisus

The settlement experiments with the cyprids were performed in static tests in 250 ml beakers using as medium filtered sea water (33-34%o salinity) containing antibiotics (sodium benzylpenicillinate (65 mg) and dihydrostreptomycin sulphate (135 mg) in 4.4 litres of medium). The incubation temperature was 7.5°C for β. balanoides and 17.3°C for B. improvisus, After 6 days the number of permanently settled and non-settled larvae was counted. In order to achieve settlement of cyprid larvae of β. balanoides, treatment of the surface with an aqueous extract of whole barnacles of the same species is needed, if adult barnacles are not present.^24,25 On the other hand, cyprids of B. improvisus settle readily without any pretreatment of the sur ace. 90-100% settlement and normal metamorphosis were observed in the controls after 6 days of incubation.

Balanus amphitrite

Between 10 and 20 cyprids were injected (using a pasteur pipette) into the wells of polystyrene 96-well plates containing serial dilution series of test compounds (4 concentra- tions). Each well contained 300 μl of test solution. Tests were carried out in four replicates. Controls were filtered seawater and seawater with the solvent used to prepare test solutions (dimethyl sulfoxide). Test plates were incubated for 24 hours at a temperature of 27°C and with a 15:9 light-dark cycle. After 24 hours the number of permanently settled and non-settled larvae was counted using a dissection microscope. The following catego- ries were regarded as permanently settled: 1) attached, non-metamorphosed cyprids, 2) decorticated cyprids, and 3) juvenile barnacles.

2.3 Biological results and discussion

The biological activities of the compounds prepared in the present work are given in Table 1. The data are expressed as EC50 values (= the compound concentration in ppm required for 50% settlement inhibition). A derivative (compound 39) reported previously by others has been included.

Table 1. EC-50 values (in ppm) for juvenile hormone analogues³

i means inactive; - means not tested or unreliable results

Some of the effects are similar to those reported for the insect Tenebrio mo//for.^26,30The pyridyl ethers are by far the most active of the three structurally different groups of com- pounds tested for activity against the cyprid stage of acorn barnacles. It appears that B. balanoides is significantly more sensitive to these compounds than β. improvisus; in the former species biological effects were observed at the ppb level of concentration.

The ether function on the pyridine ring should be at the 3-position. The significance of the ether oxygen, however, may be questioned since the 3-alkylpyridine derivative 51 was highly active, and the related compounds 52-54 exhibited considerable activity as well. Furthermore, replacing the ether oxygen with sulfur does not cause a significant decrease in activity, indicating that the degree of polarity at this end of the molecule is not crucial for activity on barnacles. Branching in the alkyl chain is not essential, but it seems to improve the activity slightly. Replacing the terpenoid moiety of the 3-alkoxy pyridine derivatives with n-alkyl chains (C9-C12) (cf. compounds 46-48) resulted in a slight drop of activity, while replacement of the n-alkyl chain with the branched and unsaturated farnesyl group (cf. compound 49) gave a compound with high activity. Unsaturation in the chain seems generally of little significance, but the presence of a cyclopropane ring reduces the activ- ity. Alkyl substitution at the 6-position of the pyridine ring has a positive effect on activity, but a slight preference for the methyl group is apparent; the presence of a heteroaromatic ring in the molecule seems quite important for activity on Balanus since phenolic ethers exhibited low or no activity at all. However, a nitrogen heterocycle does not seem to be critical since significant activity was observed for the thiophene derivative 57, although the ring must be aromatic (cf. compounds 16, 55, 56, 58). This may just mean that the actual receptor in the barnacles prefers a planar ring containing a heteroatom at this position in the molecule. It is interesting to note that the pyrimidine analogue 50 is active although less so than compound 2. The enantiomers of compounds 2 and 5²⁸ were also tested in order to obtain information about the receptor. The EC-50 value for (S)-2 was of the same order as that of the race- mic mixture, while (R)-2 was only one tenth as active. However, both (R)- and (S)-5 gave 5 EC-values identical to that of the racemic mixture. These contradictory results leave unanswered the question about the enantiomeric preference of the receptor.

Of particular interest is the lack of activity observed for Altozar/ZR 512 (39), a commercially available insect larvicide recommended for fresh water use.²⁸ Absence of activity 10 was also observed for the structurally similar esters 41-45. We have also tested a number of precocene analogues which are chromanone derivatives causing premature metamorphosis in certain insect species.²⁹ The compounds were inactive or only marginally active

30 towards both species of barnacles.

15

EXAMPLE 3

The antifouling performance of juvenile hormone analogues in paint formulation

20 3.1 Introduction

The purpose of this experiment was to evaluate the antifouling effect of certain juvenile hormone analogues identified in the present study. Thus, some of the juvenile hormone analogues identified as being biologically active were incorporated in a paint formulation. 25 These paint formulations were subsequently applied to panels that were immersed in seawater and the fouling attachment was measured regularly.

In the below field experiments, the following juvenile hormone analogues were tested for their antifouling efficacy in a paint formulation: 2 (5-(3',7'-Dimethyloctyloxy)-2- 30 methylpyridine), 6 (5-(3',7'-Dimethylocta-2',6'-dienyloxy)-2-methylpyridine), F1(3-[2'-(4"- Phenoxyphenoxy)ethoxy]pyridine) and 5 (5-(3',7'-Dimethyloct-6'-enyloxy)-2- methylpyridine).

The antifouling paint was prepared by blending and subsequently grinding for one hour: 35 30 g of binders (15 g acrylate solution and 15 g rosin solution, both 60% solutions in aro- matic hydrocarbon solvent; the acrylate was a copolymer of butyl methacrylate, methacrylic acid and methyl methacrylate), 35 g of pigments (30 g zinc oxide and 5 g titanium dioxide), 15 g of extenders (7 g carbonate and 8 g silicate), 8 g of additives (3 g poly vinyl ethyl ether, 1 g bentonite with ethanol and up to 4 g active ingredients; 2 g juvenile hormone analogue (low level), 4 g juvenile hormone analogue (high level) and 2 g juvenile hormone analogue + 2 g algicide (2-methylthio-4-tert-butylamino-6-cyclopropylamino- triazine) in combination and 12 g solvents (8 g aromatic hydrocarbons and 4 g 2-metoxy- 1-methylethyl). Thus, at "low level", the amount of juvenile hormone analogue was 2.0% by weight, and at "high level" 4.0% by weight.

3.2 Sea water exposure of antifouling paints

The antifouling effectiveness of the tested juvenile hormone analogues against marine organisms was evaluated by exposure tests in tropical seawater (Singapore). For this purpose, paint compositions comprising juvenile hormone analogues were applied on test panels of polyvinyl chloride (20 x 30 x 0.5 cm).

The test panels were degreased and subsequently coated with the antifouling paint for 48 hours. The thickness of the dry film was 100-150 μm. The test panels were mounted on larger frames and immersed in seawater at a depth of 0.5-1 m for 8 months.

The fouling attachment on the test panels was measured regularly, and a rating of the performance was determined. The calculation of the rating was based on the amount and type of fouling present on the test panel

The fouling on the test panels was rated from 0 to 4. Traces of fouling were rated 1 (0- 25% of surface), slight fouling 2 (25-50% of surface), medium fouling 3 (50-75% of surface) and heavy fouling 4 (75-100% of surface). Each fouling organism was given a weight as shown in the Table 2 below. Table 2

The fouling organisms referred to in Table 2 are as follows:

Slime: Bacteria, microalgae and protozoa.

Light slime is easily removed from the surface.

Dense slime is not easily removed from the surface.

Algae: Green algae, red algae and brown algae. Animals: Barnacles, tubeworms, mussels, hydroids and bryozoa.

The total fouling resistance was calculated by adding up the weightings and then subtract from 100. Zero growth then gives the rating 100 (100-0), and heavy fouling gives the rating 0 (100-100). The antifouling performance was rated as follows: excellent: 98-100, very good: 90-98; good: 70-90; poor: 50-70 and bad: 0-50.

3.3 Field experiment results and discussion

The results after seawater exposure of test panels with paint formulations containing JHA in Singapore are given in Table 3

Table 3. Ratings of test panels after 4 and 8 months of seawater exposure in tropical seawater (Singapore).

The test panels onto which paint compositions comprising juvenile hormone analogues had been applied, were free from barnacle fouling (microorganisms only) during the test period (8 months). Thus, it is seen from the above Table 2, that all paint compositions comprising the juvenile hormone analogues had a performance which was rated as "very good" (a rating between 90-98).

In contrast hereto, the control test panel (Blank) without paint composition comprising juvenile hormone analogues was almost covered with barnacles after 4 months and completely covered after 8 months. After 4 months the rating was "poor" and after 8 months the rating was "bad" (rating 0).

REFERENCES

1. Gilbert, L. I. (ed), The juvenile Hormones , Plenum Press, New York 1976.

2. Gade, G.; Hoffmann, K.H.; Spring, J.H. Physiol. Rev. 1997, 77, 963.

5 3. Slama, K.; Romanuk, M.; Sorm, F. Insect Hormones and Bioanalogues, Springer- Verlag, New York 1974 a) p. 195 b) p. 204 c) p. 196 d) p. 443.

4. Kramer, S. J.; Law, J. H. Ace. Chem. Res. 1980, 13, 297.

5. Laufer, H.; Borst, D.; Baker, F. C; Baker, F. C. Carrasco, O; Sinkus, M., Reuter, C. C; Tsai, L. W.; Schooley, D. A. Science 1987, 235, 202.

10 6. Gomez, E. D.; Faulkner, D. J.; Newman, W. A.; Ireland, C. ibid., 1973, 179, 813.

7. Ramenofsky, M.; Faulkner, D. J.; Ireland, C. Biochem. and Biophys. Res. Commun., 1974, 60, 172.

8. Christiansen, M. E.; Costlow, J. D.; Monroe, R. J. Mar. Biol., 1977, 39, 269.

9. Templeton, N. S.; Laufer, H. J. Invertebr. Reprod., 1983, 6, 99. 15 10. Skattebøl, L; Stenstrøm, Y.; Acta Chem. Scand. 1985, B39, 291.

11. Malhotra, S. K. French Pat. 2, 260, 255 (1977); Chem. Absstr. 1976, 84, 135291a.

12. Montavon, M.; Lindlar, H. Marbet, R. Rϋegg, R.; Ryser, G. Sauey, G.; Zeller, P.; Isler, O. Helv. Chim. Acta 1957, 40, 1250.

13. Ames, D. E.; Archibald, J. L, J. Chem. Soc, 1962, 1475.

20 14. Blau, N. F.; Wang, T. T. S.,; Buess, C. M. J. Chem. Eng. Data 1970, 15, 206.

15. Kleveland, K.; Skattebøl, L.; Sydnes, L. Acta Chem. Scand. 1977, B31 , 463.

16. Heltzig, M.; Gόbel, W.; H-J. J. Prakt. Chem. 1969, 311, 174.

17. Isler, O.; Rϋegg, R.; Chopart-dit-Jean, L.; Wagner, H.; Bernhard, K.; Helv. Chim. Acta 1956, 39, 897.

25 18. Henrick, C. A.; Willy, W. E.; Baum, J. W.; Baer, T. A.; Garcia, B. A.; Mastre, T. A. ; Chang, S. M. J. Org. Chem. 1975, 40, 1.

19. Skattebøl, L. Acta Chem. Scand. 1963, 17, 1683.

20. Tamura, M.; Kochi, J. Synthesis 1971 , 303.

21. Maklyaev, F. L; Petrova, G. B. J. Gen. Chem. USSR 1963, 33, 3862. 30 22. Fedorov, B. P.; Stoyanovich, F. M. ibid. 1963, 33, 2194.

23. Redfern, R.E. in Meun, J. J.; Beroza, M.(eds.) Insect Juvenile Hormones, Academic Press, New York 1972, p. 250.

24. Grisp, D. J.; Meadows, P. S. Proc. Roy. Soc. 1962, B156, 500.

25. Crisp, D. J.; Meadows, P. S. ibid. 1963, B158, 364. 26. Solli, H.; Berg Madsen, H.; Hoist, P. L.; Klemmensen, P. D. Pestic. Sci. 1976, 7, 503.

27. Henrick, C. A.; Staal, G. B. Siddall, J. B. J. Agric. Food Chem. 1973, 21 , 354.

28. Henrick, C. A. Unpublished results.

29. Bowers, W. S.; Ohta, T.; Cleere, J. S.; Marsella, P. A. Science 1976, 193, 542.

5 30. Skattebøl, L; Hovde, H.; Kleveland, K.; Nilsen, N. O.; Stenstrøm, Y. Unpublished results.

31. Henrick, C. A.; Anderson, R. J.; Staal, G. B.; Ludvik, G. F. J. Agric. Food Chem. 1978, 26, 542.

32. Henrick, C. A.; Willy, W. E.; Staal, G. B. J. Agric. Food Chem. 1976, 24, 207.

10 33. Henrick, C. A.; Willy, W. E.; Garcia, B. A.; Staal, G. B. J. Agric. Food Chem. 1975, 23, 396.

Claims

1. A juvenile hormone analogue (juvenoid) compound selected from the group consisting of

(i) a compound of the general formula I

where R¹ is alkyl or branched alkyl including alkenyl, alkadienyl and alkatrienyl, optionally substituted isoprenoid or alkoxy substituted alkyl, R² is hydrogen or alkyl, X is oxygen, sulfur, methylene, carbinol or carbonyl, Y is nitrogen or methinine and Z is nitrogen, methine or nitrogen oxide;

(ii) a compound of general formula II

where R¹ is 2,2-dimethylcyclopropyl, 2,2-dihalo-3,3-dimethylcyclopropyl, 2-methyl-1- propenyl or 3-methyl-1 ,2-butadienyl, R² is hydrogen or methoxy, R³ is alkyl, alkenyl, acetyl, formyl or carbomethoxy, R⁴ is hydrogen or R³ and R⁴ together is methylenedioxy and X is oxygen or sulfur; (iii) a compound of the general formula III

5 where R¹ is 2-methylbutyl, 2,2-dimethylcyclopropyl or 2,2-dihalo-3,3-dimethylcyclopropyl and R² is methyl, ethyl or isopropyl,

(iv) a compound of the general formula IV

where X is oxygen or sulfur and Ar is a heteroaromatic group, and

(v) a compound selected from the group consisting of

15

55: 4-Octylmorpholine; 56: 1-Octylpiperidine; 58: 1 ,4-dioctylpiperazine; 59: 3-(3',7'-Dimethyloctyloxy)pyridine; 20 60: 3-(3',7^,-Dimethyloctylsulfanyl)pyridine;

1-205: 3,3-dimethylocta-2,6-dienoic acid dimethylamide; and 1-265: 3,3-dimethyl-3-oxaundecanoic acid dimethylamide

subject to the limitation that the compound is not 5-(3',7'-Dimethylocta-2',6'-dienyloxy)-2- 25 methylpyridine, 3-(3',7^,-Dimethylocta-2^,,6'-dienyloxy)pyridine, 5-(3',7'-Dimethylocta-2^,,6'- dienylsulfanyl)benzo[1 ,3]dioxole or Methyl 7,11-dimethyl-dodeca-2,4-dienoate.

2. A compound according to claim 1 of the general formula I where R¹ is alkyl.

30 3. A compound according to claim 1 of the general formula I where R¹ is branched alkyl.

4. A compound according to claim 1 of the general formula I where R¹ is alkoxy substituted alkyl.

5. A compound according to claim 1 of the general formula I where R¹ is isoprenoid in- eluding cyclopropyl substituted isoprenoid such as farnesyl.

6. A. compound according to claim 5 of the general formula I where R¹ is gem- dihalocyclopropyl substituted isoprenoid.

7. A compound according to any of claims 1-6 of the general formula I where X is oxygen.

8. A compound according to any of claims 1-6 of the general formula I where X is sulfur.

9. A compound according to any of claims 1-8 of the general formula I where Y is nitro- gen.

10. A compound according to any of claims 1-9 of the general formula where Z is nitrogen.

11. A compound according to claim 1 of the general formula I that is selected from the group consisting of

1 : 5-(7'-Ethoxy-3^,,7'-dimethyloctyloxy)-2-methylpyridine;

2: 5-(3',7'-Dimethyloctyloxy)-2-methylpyridine; R-2 (3'f?)-5-(3',7'-Dimethyloctyloxy)-2-methylpyridine;

S-2: (3'S)-5-(3',7'-Dimethyloctyloxy)-2-methylpyridine;

3: 2-Methyl-5-(7'-methyloctyloxy)pyridine;

4: 2-Methyl-5-octyloxypyridine;

5: 5-(3',7'-Dimethyloct-6'-enyloxy)-2-methylpyridine; 6: 5-(3',7'-Dimethylocta-2^,,6^,-dienyloxy)-2-methylpyridine;

7: 3-(3',7'-Dimethylocta-2',6^,-dienyloxy)pyridine;

8: 5-[5^,-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3^,-methylpent-2^,-enyloxy]-2- ethylpyridine;

9: 5-[5^,-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3^,-methylpent-2'-enyloxy]-2- methylpyridine; 10: 5-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2-ethylpyridine;

11 : 5-[5^,-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2-methylpyridine;

12: 5-[5'-(2",2"-Dimethylcyclopropyl)-3^,-methylpentyloxy]-2-methylpyridine;

13: 5-(3',7'-Dimethyloctylsulfanyl)-2-methylpyridine; 5 14: 2-(3',7'-Dimethylocta-2^,,6'-dienyloxy)pyridine;

15: 2-(3',7'-Dimethyloctylsulfanyl)pyridine;

16: 3-(3',7'-Dimethyloctyloxy)-1-methylpiperidine;

46: 2-Methyl-5-nonyloxypyridine;

47: 2-Methyl-5-undecyloxypyridine; 10 48: 5-Dodecyloxy-2-methylpyridine;

49: 2-Methyl-5-(3',7', 11 '-trimethyldodeca-2',6', 10'-trienyloxy)pyridine;

51 : S-^'.δ'-Dimethylnony pyridine;

52: 3-(4',8'-Dimethylnonyl)pyridine-N-oxide;

53: 4,8-Dimethyl-1-pyridin-3-ylnonan-1-ol; 15 54: 4,8-Dimethyl-1-pyridin-3-ylnonan-1-one;

61 : 3-(7'-Ethoxy-3',7'-dimethyloctyloxy)pyridine;

F-1 : 3-[2'-(4"-Phenoxyphenoxy)ethoxy]pyridine;

F-3: 2-[2'-(4"-Phenoxyphenoxy)ethoxy]pyridine; and

F-4: 3-(4'-Phenoxybenzyloxy)pyridine. 20 1-230: 2-methyl-5-decyloxypyridine

12. A compound according to claim 1 of the general formula II having saturated side chains to the aromatic ring.

25 13. A compound according to claim 1 of the general formula II where R³ and R⁴ together is methylenedioxy.

14. A compound according to claim 1 of the general formula II where X is oxygen.

30 15. A compound according to claim 1 of the general formula II that is selected from the group consisting of

17: 5-(3',7'-Dimethyloctyloxy)benzo[1 ,3]dioxole; 18: 5-(3',7'-Dimethylocta-2',6'-dienyloxy)benzo[1 ,3]dioxole; 35 19: 5-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]benzo[1 ,3]dioxole; 20: 5-[5^,-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3^,-methylpent-2^,- enyloxy]benzo[1 ,3]dioxole;

21 : 5-[5'-(2",2"-Dibromo-3",3"-dimethylcyclopropyl)-3^,-methylpent-2'- enyloxy]benzo[1 ,3]dioxole; 5 22: 5-(3',8'-Dimethylnona-2',6',7^,-trienyloxy)benzo[1 ,3]dioxole;

24: 1-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-4-ethylbenzene;

25: 1-[5'-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-4- ethylbenzene;

26: 1-[5^,-(2",2"-Dibromo-3",3"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-4- 10 ethylbenzene;

27: 1 -(3\8'-Dimethylnona-2\6\7'-trienyloxy)-4-ethylbenzene;

28: Methyl 4-[5^,-(2",2"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]benzoate;

29: Methyl 4-[5'-(2",2"-dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- enyloxyjbenzoate; 15 30: Methyl 4-[5'-(2",2"-dibromo-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- enyloxyjbenzoate;

31 : 1 -Acetyl-4-[5'-(2",2"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]benzene;

32: 1-Acetyl-4-[5'-(2",2"-dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- enyloxyjbenzene; 20 33: 1 -Acetyl-4-[5^,-(2",2"-dibromo-3",3"-dimethylcyclopropyl)-3'-methylpent-2'- enyloxyjbenzene;

34: (3,7-Dimethyloctyloxy)benzene;

35: 4-[5'-(2",2"-Dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-3-methoxybenzaldehyde;

36: 4-[5'-(2",2"-Dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2^,-enyloxy]-3- 25 methoxybenzaldehyde;

37: 1-[5'-(2",2"-Dichloro-3",3"-dimethylcyciopropyl)-3'-methylpent-2'-enyloxy]-2-methoxy-

4-propenylbenzene; and

38: 4-Allyl-1-[5^,-(2",2"-dichloro-3",3"-dimethylcyclopropyl)-3'-methylpent-2'-enyloxy]-2- methoxybenzene. 30

16. A compound according to claim 1 of the general formula III that is selected from the group consisting of

40: Methyl 9-(2^',2^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate; 35 41 : Ethyl 9-(2^',2^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate; 42: Isopropyl 9-(2^',2^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate; 43: Methyl 9-(2^',2^'-dichloro-3^'3^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate; 44: Ethyl 9-(2^',2^'-dichloro-3^'3'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate; and 5 45: Isopropyl 9-(2^',2^'-dichloro-3^'3^'-dimethylcyclopropyl)-3,7-dimethylnona-2E,4E-dienoate

17. A compound according to claim 1 selected from the group consisting of

50: 5-(3',7'-Dimethyloctyloxy)-2-methylpyrimidine (of general formula IV); 10 57: 2-(3',7'-Dimethyloctylsulfanyl)thiophene (of general formula IV;

55: 4-Octylmorpholine;

56: 1-Octylpiperidine;

58: 1 ,4-Dioctylpiperazine;

59: 3-(3',7'-Dimethyloctyloxy)pyridine; 15 60: 3-(3',7'-Dimethyloctylsulfanyl)pyridine;

I-205: 3,3-dimethylocta-2,6-dienoic acid dimethylamide; and

I-265: 3,3-dimethyl-3-oxaundecanoic acid dimethylamide

18. A juvenile hormone analogue compound that, at a concentration of at the most 10

20 ppm, inhibits the settlement and/or attachment of cyprid larvae of a Cirripedia species selected from the group consisting of Balanus balanoides, Balanus improvisus and Balanus amphitrite onto a solid surface in contact with an aqueous medium containing said concentration of the compound and/or the metamorphosis of such larvae in the aqueous medium, by 50% (EC-50), relative to such cyprid larvae contained in a medium not contain-

25 ing the compound, wherein the EC-50 for any of said Balanus species is determined as defined hereinbefore.

19. A compound according to claim 18 that inhibits said settlement, attachment and/or metamorphosis at a concentration of at the most 1 ppm, such as at the most 50 ppb in-

30 eluding at the most 30 ppb, such as at the most 10 ppb.

20. A compound according to claim 18 which is a compound according to any of claims 1- 17.

21. A method of controlling the fouling of a surface with a living organism, the method comprising applying to said surface an effective amount of a juvenile hormone analogue compound.

5 22. A method according to claim 21 wherein the juvenile hormone analogue compound is a compound according to any of claims 1-20.

23. A method according to claim 21 wherein the living organism is a crustacean species.

10 24. A method according to claim 23 wherein the crustacean species is a Cirripedia species.

25. A method according to claim 24 wherein the Cirripedia species is selected from the group consisting of Balanus galeatus, Balanus amphitrite, Elminius modestus, Balanus

15 improvisus, Balanus balanoides and Balanus crenatus.

26. A method according to any of claims 22-25 wherein the surface is a surface that is at least occasionally immersed in water.

20 27. A method according to claim 26 wherein the surface is a ship's hull.

28. A method according to claim 21 wherein the compound is applied in a coating composition.

25 29. A method according to claim 28 wherein the coating composition is a paint composition.

30. A method according to claim 28 wherein the coating composition comprises at least one further biocidally active compound.

30

31. A method according to claim 22 wherein the compound is a compound according to claim 1 of general formula I where Z is nitrogen.

32. An antifouling composition comprising a compound according to any of claims 1-20. 35

33. A composition according to claim 32 which is a paint composition.

34. A composition according to claim 33 wherein the compound is present in an amount of 0.1-50% by weight of the composition.

5

35. A composition according to claim 34 wherein the compound is present in an amount of 0.5-25% by weight of the composition, including in an amount of 2-10% by weight of the composition.

10 36. A composition according to claim 32 or 33 that contains at least one further antifouling agent.

37. A composition according to claim 36 wherein the at least one further antifouling agent is an algicide.

15

38. A composition according to claim 36 wherein the at least one further antifouling agent is selected from the group consisting of copper metal, cuprous oxide, cuprous thiocya- nate, bis (2-pyridinethiol 1 -oxide) zinc, bis (2-pyridinethiol 1 -oxide) copper, 4,5-dichloro-2- octyl-3(2H)-isothiazolinone, 2-methylthio-4-tert-butylamino-6-cyclopropylamino-triazine,

20 zinc ethylenebis (dithiocarbamate) and pyridine triphenylborane.

39. A method of preparing a compound according to claim 1.

40. A method according to claim 39 wherein the compound is an ether compound, the 25 method comprising the steps of reacting an aromatic hydroxy or thiohydroxy compound with a metal hydride to give an alkoxide or thioalkoxide which is subsequently reacted with an alkyl halide to give the ether.

41. A method according to claim 40 wherein the resulting ether compound is selected 30 from the group consisting of compounds 1-38, 46-50, 59 and 60 as defined herein.

42. A method according to claim 39 or 40 wherein the compound is a terpenoic cyclopropane derivative, the method comprising dihalocyclopropanating an alkene followed by reduction of the halide of the dihalocyclopropanes by sodium in liquid ammonia to give the

35 terpenoic cyclopropane derivative.

43. A method according to claim 42 wherein the resulting terpenoic cyclopropane derivative is selected from the group consisting of compounds 8-12, 19-21, 24-26, 28-33, 35-38 and 40-45 as defined herein.

5

44. A method according to claim 39 or 40 wherein the compound is a terpenoic allene derivative, the method comprising dihalocyclopropanating an alkene followed by treating the dihalocyclopropane with methyl lithium to give the corresponding allene.

10 45. A method according to claim 44 wherein the terpenoic allene derivative is selected from the group consisting of compounds 22 and 27 as defined herein.

46. Use of a juvenile hormone analogue compound as an antifouling agent in a paint composition.

15

47. Use according to claim 46 where the compound is a compound according to claim 1.