JPS6234001B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a nematicide containing a 1-thienyl alcohol derivative as an active ingredient. In Japan's intensive agriculture, in recent years, especially for vegetables, the establishment of the designated production area system, institutionalization of cultivation, and year-round cultivation have progressed, and damage caused by soil diseases and pests due to continuous cultivation has become a major problem for various crops in various regions. I'm getting used to it. One of the important causes is nematode damage. On the other hand, many drugs have been developed and put into practical use to control these harmful soil organisms. Many of them diffuse as gases in the clay pot and become active when they come into contact with this gas. For example, EDB (1,2-dibromoethane), DD (1,3-dichloropropene and 1,2-dichloropropane), chloropicrin (trichloronitromethane), methyl bromide, Carbam (N-methyldithiocarbamate salt), DCIP
(Bischloroisopropyl ether), DBCP
(1,2-dibromo-3-chloropropane) is a typical example. Although these chemicals gasify at room temperature and easily diffuse through the container, they tend to escape from the container, require troublesome work such as covering, and have restrictions on storage and use such as flammability, toxicity, and irritation. . In addition, the effects are not specific and the crops to which it can be applied are limited, and it is inconvenient that it can only be planted after degassing. As a result of extensive research into drugs for controlling harmful soil organisms, the present inventors discovered that a specific thiophene derivative has a unique action and completed the present invention. The present invention is based on the general formula (In the formula, R is hydrogen or a lower acyl group, R ₁ is hydrogen or a lower alkyl group, and R ₂ is a lower alkyl group containing at least one halogen.) It is a nematocide that is The 1-thienyl alcohol derivative according to the active ingredient of the present invention can be easily synthesized by Friedel-Crafts reaction of thiophene and the corresponding aldehyde, reduction of acylthiophene, or addition reaction of dihaloalkyl to acylthiophene. Representative examples of these compounds are shown below along with synthesis examples, but the compounds related to the active ingredients of the present invention are not limited to these only. Synthesis Example 1 Synthesis of 2,2,2-trichloro-1-(2-thienyl)ethanol Under an argon atmosphere, titanium tetrachloride (6.84 g) was placed in a methylene chloride (350 ml) solution under ice-cooling and stirring.
Titanium tetraisopropoxide (51.1 g) was added. After 10 minutes, a solution of thiophene (31.1 g) in methylene chloride (25 ml) was added, followed by chloral (65.4
A solution of g) in methylene chloride (25 ml) was added dropwise over 1 hour. After stirring for a further 1 hour, water (350ml) was added. The separated methylene chloride layer was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified by distillation to obtain 67.8 g of the desired product. bP92−98℃/0.5mmHg. IR (liquid film):
3425, 1065, 1044, 822, ^{710cm -1} . NMR
(CDCl ₃ ) δ: 3.48 (d, 1H), 5.40 (d, 1H),
6.88−7.50 (m, 3H). Synthesis Example 2 Synthesis of [2,2,2-trichloro-1-(2-thienyl)]ethyl acetate 2,2,2-trichloro-1-(2-thiophene)ethanol (15.5g) and acetyl chloride (15.5ml) ) After heating the mixture with reflux for 6 hours,
Acetyl chloride was distilled off under reduced pressure. The residue was dissolved in ether and dried over saturated brine and saturated sodium hydrogen carbonate. The solvent was distilled off under reduced pressure to obtain the desired product as white crystals. mp63.0−65.0℃NMR
(CDCL ₃ ) δ: 2.15 (S, 3H), 6.70 (S, 1H),
6.9−7.5 (m, 3H). IR (KBr tablets): 1750, 1215, 1040, 930, 800,
720 cm ^-1 . Synthesis Example 3 Synthesis of 1-(2-thienyl)-1-dichloromethylethanol Methylmagnesium iodine was prepared from magnesium turnings (0.54 g) and methyl iodide (3.72 g) in dry ether (30 ml) under an argon atmosphere. I prepared Dido's Grignard reagent. This Grignard reagent was added to a solution of 2-(dichloroacetyl)thiophene (3.60 g) in ether (15 ml).
It was added dropwise at a temperature below 10°C. After the dropwise addition, stirring was continued for 16 hours at room temperature, and then a saturated ammonium chloride aqueous solution (20 ml) was added.
was added and extracted with ether. The ether layer was washed with saturated saline, dried over anhydrous sodium sulfate,
The ether was distilled off to obtain the desired product as an oil.
NMR (CDCl ₃ ) δ: 1.83 (S, 3H), 2.98 (S,
1H), 5.76 (S, 1H), 6.8-7.4 (m, 3H). IR (liquid film): 3500, 3100, 2980, 1370, 1225,
795, 705 cm ^-1 . These 1-thienyl alcohol derivatives can be mixed with various carriers and used in any form such as emulsions, oils, granules, and wettable powders, depending on the intended use. The carrier used here may be either liquid or solid, or a combination thereof. Examples include solid carriers such as bentonite, talc, kaolin clay, and diatomaceous earth, and inert solvents such as xylene, isophorone, cyclohexanone, and kerosene.
Furthermore, during formulation, a surfactant or the like may be added to impart emulsifying and dispersing properties. The formulations can be readily obtained by commonly used concentrate manufacturing techniques. The drug according to the present invention can be used not only alone, but also in combination with other agricultural chemicals such as herbicides, fungicides, insecticides, or fertilizers. Hereinafter, the excellent effects of the compound according to the active ingredient of the present invention will be explained with reference to test examples. Test Example 1 Control effect on sweet potato knot nematode using tomatoes as an indicator 70g of soil contaminated with sweet potato knot nematode (Meloidogyne incognita) grown on sweet potatoes as a parasite was placed in a clay pot with a diameter of 5.5 cm and a height of 5.5 cm. A predetermined amount of the emulsion prepared according to Example 1 was diluted with water and poured onto the surface of a clay pot. Seven days after treatment, tomato seeds were sown at 10 seeds per pot. The DCIP agent used as a control agent was mixed into the soil, and the EDB was covered for 2 days after the spot injection treatment, and the gas was degassed at the time of sowing. Testing is performed at glass room temperature (25-30℃)
40 days after treatment, the degree of parasitic root galls and chemical damage were investigated. In addition, the degree of root gall and chemical damage were expressed by the following values. The results are shown in Table 1. Note that the test was repeated three times. Indication of parasitic root gall level 0... None 1... Slight 2... Medium 3... High 4... Indication of phytotoxicity -... No phytotoxicity observed ±... Growth slightly poor +... Poor growth =... ...Growth extremely poor = ...Does not burrow or dies

【table】

[Table] Test Example 2 Control effect on sweet potato knot nematodes using cucumbers as an indicator in a large pot A 1/10000a pot (height 14
cm) and mixed with a predetermined amount of granules prepared according to Example 2, and the control drug was treated in the same manner as in Test Example 1. Ten days after the treatment, seven cucumber seeds were sown per pot. One month after sowing, the degree of parasitic root galls and chemical damage were investigated. The indication of the degree of parasitic root gall and chemical damage is in accordance with Test Example 1. The results are shown in Table 2. The test was repeated three times.

[Table] As described above, the compound according to the active ingredient of the present invention exhibits excellent effects against Nematode nematodes that cause great damage to crops, and does not cause any phytotoxicity to tomatoes and cucumbers. Examples of formulations are shown below. All parts in the text indicate parts by weight. Example 1 Emulsion 2.2.2-trichloro-1-(2-thienyl)
Ethanol 2 parts Methanol 48 parts Acetone 48 parts Solpol-900A (emulsifier, trademark of Toho Chemical Co., Ltd.)
1 part Nonal 205 (emulsifier, Toho Chemical Co., Ltd. trademark) 1 part The above were mixed and dissolved to form an emulsion. Example 2 Granules 2,2,2-trichloro-1-(2-thienyl)
Ethanol 25 parts Granular diatomaceous earth 75 parts Granular diatomaceous earth was impregnated with the active ingredient to form a granule. Example 3 Wettable powder 1-(2-thienyl)-1-dichloromethylethanol 30 parts Carplex (trademark of Shionogi & Co., Ltd.) 25 parts Kaolin clay 40 parts Solpol 5039 (dispersant, trademark of Toho Chemical Co., Ltd.) 5 parts or more were mixed and ground to form a wettable powder. Example 4 An oil agent [2.2.2-trichloro-1-(2-thienyl)] 50 parts of ethyl acetate and 50 parts of orthochlorotoluene were mixed and dissolved to obtain an oil agent. Example 5 Granules [2.2.2-trichloro-1-(2-thienyl)]ethyl acetate 30 parts Carplex 13 parts Bentonite 52 parts Surf-Inol TGE (Air Products and
Chemicals Co., Ltd. trademark) 2 parts Nonal 208 (emulsifier, Toho Chemical Co., Ltd. trademark) 3 parts The above ingredients were mixed and made into granules by a normal granulation method.

Claims (1)

[Claims] 1. General formula (In the formula, R is hydrogen or a lower acyl group, R ₁ is hydrogen or a lower alkyl group, and R ₂ is a lower alkyl group containing at least one halogen.) Nematicide.