IL32054A - Alkoxy vinylphosphonodithioates and their use for killing nematodes - Google Patents

Description

n mono 3 mann Alkoxyvinylphosphonodithioates and their use for killing nematodes PARDBSTP ftjBTtli iR BATIR AKf IFNGESELLSCHAFE C. 30366 32054/2 1 In U.S. Patent No. 3,481,731 there is described the preparation of compounds having the formula R where R^ is lower alkyl, an R2 and are alkyl of 1 to 8 carbon atoms, phenyl, lower alkyl phenyl or chlorophenyl . R2 and R^ can be the same or different. These compounds are disclosed as being good herbicides.

It has now been found that some of the compounds within this formula have good nematocide activity. Surprisingly, however, this is not true of all compounds of this general type. Thus if R^ is methyl, n-propyl, isopropyl or t-butyl che compounds exhibit nematocidal activity but if ^ is ethyl, n-butyl, isobutyl or isooctyl there is no nematocidal activity. Also if R^j is replaced by p-chlorophenyl there is no nematocidal activity. -B e^&ea?ab-l-y- -A-,--a^-d- e.¥-e-±e*erF-M2s& -f -&<>&b--*p& £-e?e.biy- As pointed out, in the above cited U.S. specification the compounds of the present invention within formula I are readily prepared by reacting an alkyl vinyl ether with phosphorus pentachloride , preferably suspended in a solvent such as carbon tetrachloride to .form the complexed 2-alkoxy-2-chloroethylphosphorus tetrachloride. The complex is treated with two moles of sulfur dioxide. Dehydrohalogenation of the intermediate form in this reaction occurs simultaneously or upon removal of the phosphorus oxychloride-thionyl chloride-solvent mixture to yield alkoxyvinylphosphonyldicbloride .

The alkoxyvinylphosphonodithioates are formed by esteri-fication of the alkoxyvinylphosphonyldichloride with a mercaptan in the presence of a tertiary amine, e.g. tri-ethylamine, tripropylamine , Ν,Ν-dimethylaniline , etc.

As alkyl vinyl ethers as starting materials there can be employed methyl vinyl ether, propyl vinyl ether, isopropyl vinyl ether and tert. butyl vinyl ether.

As mercaptans there can be used methyl mercaptan, ethyl mercaptan, propyl mercaptan, isopropyl mercaptan, tfutyi mercaptan, isobutyl mercaptanj The most preferred compound tested as a nematocide was S,S-diisopropyl-2-metboxyvinylpbospbonodithioate .

Other compounds useful as nematocides within the invention are S,S-dietbyl-2-methoxyvinylphosphonodithioate, 32054/2 S,S-dimethyl-2-methoxyvinylphosphonodithioate, S,S-dipropyl 2-methoxylvinylphosphonodithioate , S, S-dibutyl-2-methoxy- · vinylphosphonodithioate , S,S-diisobutyl-2-methoxyvinyl-phosphonodithioate , S, S-di-sec. butyl-2-methoxyvinylphos-phonodithioate , S,Q-di-t-butyl-2-metboxyvinylphosphono-ditbioate , S-ethyl-S-isopropyl-2-methoxyvinylphosphono-dithioate , S-metbyl-S-propyl-2-metboxyvinylphospbonoditbio-ate , S-isopropyl-S-iosbutyl-2-methoxyvinyl--phospbonodithioate , S, S-dimethyi-2-propoxyvinylph0sphono-ditbioate , S, S-dimethyl-2-t-butoxyvinylphosphonodithioate , S,S-dietbyl-2-propoxyvinylpbosphonodithioate , S,S-diethyl-2-isopropoxyvinylphospbonodithioate , S,S-diethyl-2-t-butoxy vinylphosphonodithioate, S,S-dipropyl-2-propoxyvinylpbos-phonodithioate, S, S-dipropyl-2-isopropoxyvinylpbosphono-dithioate , S, S-dipropyl-2-t-butoxyvinylphosphonodithioate , S, S-diisopropyl-2-propoxyvinylphosphonoditbioate , S,S-di-isopropyl-2-isopropoxyvinylphospbonoditbioate, S, S-diiso-propyl-2-t-butoxyvinylphospbonodithioate , S,S-dibutyl-2— propoxyvinylphosphonodithioate , S, S-dibutyl-2-isopropoxy-vinylphosphonoditbioate , S,S-dibutyl-2-t-butoxyvinylphos-phonodithioate, S,S-diisobutyl-2-propoxyvinylphosphonodi-thioate, S,S-diisobutyl-2-isopropoxyvinylphosphonodithioate S,S-diisobutyl-2-t-butoxyvinylphosphonodithioate.

♦ The compounds employed in this invention are all high boiling liquids.

Unless otherwise indicated all parts and percentages are by weight.

Le A 12050 - 3 - Example 1 29 grams (0.5 mole) of methyl vinyl ether was added to a stirring suspension of 208 grams (1 mole) of phosphorus pentacbloride in 8 - 10 volumes of carbon tetrachloride.

The reaction mixture was cooled to 10 - 20°C. throughout . the addition. After the addition was completed, the reaction mixture was allowed to warm to room temperature (25°C.) and was then stirred .for 12 - hours.

Gasous sulfur dioxide was the bubbled into the stirring suspension at a rapid rate. Cooling was maintained at - 20°C throughout the addition. Completion of the reaction was evidenced by disappearance of the solid phase and the formation of a clear solution. The 2-methoxyvinyl phosphonyl dichloride was obtained by direct distillation of the reaction mixture. .

Example 2 The procedure of example 1 was repeated replacing the methyl vinyl ether by 0.5 mole of propyl vinyl ether to prepare 2-propoxyvinyl phosphonyl dichloride.

Example 3 The procedure of example 1 was repeated replacing the methyl vinyl ether by 0.5 mole of isopropyl vinyl ether to prepare 2-isopropoxyvinyl phosphonyl dichloride.

Example 4- The procedure of example 1 was repeated replacing the methyl vinyl ether by 0. mole of t-butyl vinyl ether to prepare 2-t-butoxyvinyl phosphonyl dichloride.

Le A 00 _ 4. _ Example 5 I7 .5 grams (0. 1 mole) of 2-(methoxy)vinyl phosphonyl dichloride was diluted with 10 volumes of dry benzene. 12.5 grams (0.2 mole) of ethyl mercaptan was then added. 20.2 grams (0.2 mole) of triethylamine was added to this stirring solution at such a dropwise rate to keep the exothermic reaction temperature at 30 - 35°0· After the addition was completed, the reaction mixture was allowed to stir until room temperature was reached (25°C.).

The reaction mixture was then washed with cold water. (If the water wash was acid, as occurred in some experiments the benzene layer was extracted with $ sodium bicarbonate solution. The benzene layer was then further washed until all washes were neutral.) The benzene layer was then dried over anhydrous sodium sulfate. The solvent was stripped in vacuo on a steam bath; and the resulting crude oil was distilled to obtain S, S-diethyl-2-methoxyvinylphosphonodi-thioate (Compound 7374) as the product.

Example 6 I 3.5 grams (0.08 mole) of 2-(methoxy) inyl phosphonyl dichloride was diluted with 10 volumes of dry benzene. 12.5 grams (0.16 mole) of isopropyl mercaptan was then added 15. grams (0. 15 mole) of triethylamine was added to this stirring solution at such a dropwise rate to keep the exothermic reaction temperature at 3 - 35°C- After the addition was completed, the reaction mixture was allowed to stir until room temperature was reached (25°C.).

The reaction mixture was then washed with cold water. (If the water wash was acid, as occurred in some experiments the benzene layer was extracted with $ sodium bicarbonate Le A 12050 - 5 - solution. The benzene layer was then further washed until all washes were neutral.) The benzene layer was then dried over anhydrous sodium sulfate. The solvent was stripped in vacuo on a steam bath ; and the resulting crude oil was distilled to obtain S,S-diisopropyl-2-metboxyvinylphospbono-dithioate (Compound 7375) as the product.

Example 7 The procedure of example 5 was repeated replacing the ethyl mercaptan by 0.2 mole of n-butyl mercaptan to obtain S,S-dibutyl-2-methoxyvinylpbospbonodithioate (Compound 7950) as the product.

Example 8 The procedure of example was repeated replacing the ethyl mercaptan by 0.2 mole of n-propyl mercaptan to obtain S,S-dipropyl-2-methoxyvinylpnospbonodithioate (Compound 8132) as the product.

Example 9 The procedure of example was repeated replacing the 2-methoxy inyl pbosphonyl dichloride by 0.1 mole of -propox inyl pbosphonyl dichloride to obtain S,S-diethyl-2-propoxyvinylphosphonodithioate (Compound 7938) as the product.

Example 10 The procedure of example 9 was repeated replacing the ethyl mercaptan by 0.2 mole of n-propyl mercaptan to obtain S,S-dipropyl-2-propoxyvinylphospbonodithioate (Compound 7939) as the product.

Le A 12050 - 6 - Example 11 The procedure of example 9 was repeated replacing the ethyl mercaptan by 0.2 mole of n-butyl mercaptan to obtain S,S-dibutyl-2-propoxyvinylphospbonoditbioate (Compound 794-0) as the product.

Example 2 The procedure of example 5 was repeated replacing the 2-metboxyvinyl phosphonyl dichloride by 0.1 mole, of 2-iso-propoxyvinyl phosphonyl dichloride to obtain S,S-dietbyl-2-isopropoxyvinylpbospbonoditbioate (Compound 7954-) as the product .

Example $ The procedure of example 12 was repeated replacing the ethyl mercaptan by 0.2 mole of isopropyl mercaptan to obtain S,S-diisopropyl-2-isopropoxyvinylphosphonodithioate (Compound 7955) as the product.

Example 1 The procedure of example 12 was repeated replacing the ethyl mercaptan by 0.2 mole of n-butyl mercaptan to obtain S, S-dibutyl-2-isopropoxyvinylphosphonoditbioate (Compound 79 ^) as the product.

Example 5 The procedure of example 5 was repeated replacing the 2-metboxyvinyl phosphonyl dichloride by 0.1 mole of 2-t-butoxyvinyl phosphonyl dichloride to obtain S,S— diethyl -2-t-butoxyvinylphosphonoditbioate (Compound 7957) as the product.

Le A 12050 - 7 - Example 16 The procedure of example 15 was repeated replacing the ethyl mercaptan by 0.2 mole of methyl mercaptan to obtain S,S-dimethyl-2-t-butoxyvinylphospbonodithioate (Compound 8009) as the product.

Example 17 The procedure of example 5 was repeated replacing the ethyl mercaptan by 0.2 mole of n-propyl mercaptan to obtain S,S-dipropyl-2-t-butox vinylphospbonodithioate (Compound 7959) as the product.

The compounds have been used successfully with the parasitic nematode Meloidogyne spp. They are also effective nematocides for saprophytic nematodes such as Panagrellus spp. and Rhabditis spp.

The nematocides of the present invention can be used alone or they can be applied together with inert solids to form dusts, or can be dispersed in a suitable liquid dilute, e.g., organic solvents or. water.

There can also be added surface active agents or wetting agents and/or inert solids in the liquid formulations. In such case, the active ingredients can be from 0.01 to 9 $ b weight of the entire composition.

As organic solvents there can be employed hydrocarbons e.g., benzene, toluene, xylene, kerosene, diesel fuel, fuel oil and petroleum naphtha, ketones such as acetone, methyl ethyl ketone and cyclobexanone , chlorinated hydrocarbons Le A 12050 - 8' - such as carbon tetrachloride, chloroform, trichloroetbylene, and perchloroethylene , esters such as ethyl acetate, amyl acetate and butyl acetate, ethers, e.g. ethylene glycol monometbyl ether and dietbylene glycol mpnomethyl ether, alcohols, e.g. methanol, ethanol, isopropanol, amy! alcohol, ethylene glycol, propylene glycol , -butyl carbitol acetate and glycerine. Mixtures of water and organic solvents, either as solutions or emulsions, can be employed.

The novel nematocides can also be applied as aerosols, e.g. by dispersing them in air by means of a compressed gas such as dichlorodifluorometbane or trichlorofluoromethane and other Freons and Genetrons, for example.

The pesticides of the present invention can also be applied with adjuvants or carriers such as. tale, pyro-phyllite, synthetic fine silica, attapulgus clay, kiesel- . gubr, chalk, diatomaceous earth, lime, calcium carbonate,^ bentoriite, fuller's earth, cottonseed hulls, wheat flour, soybean flour, pumice, tripoli, wood flour, walnut shell flour, redwood flour and liqnin.

As stated, it is frequently desirable to incorporate . a surface active agent in the pesticidal compositions of the present invention. Such surface active or wetting agents are advantageously employed in both the solid and liquid compositions. The surface active agent can be anionic, cationic or nonionic in character. .

Typical classes of surface active agents include alkyl sulfonate salts, alkylaryl sulfonate salts, alkylaryl poly-ether alcohols, fatty acid esters of polyhydric alcohols and the alkylene oxide addition products of such esters, and addition products of long chain mercaptans and alkyle e Le A 12030 - 9 - oxides. Typical examples of such surface active agents include the sodium alkylbenzene sulfonates having 10 to 18 carbon atoms in the alkyl group, alkylpbenol ethylene oxide condensation products, e.g. p-isooctylphenol condensed with 10 ethylene oxide units, soaps, e.g. sodium stearate and potassium oleate, sodium salt of propyl-naph halene sulfonic acid, di (2-ethylbexyl) ester of sodium sulfosuccinic acid, sodium lauryl sulfate, sodium decane sulfonate, sodium salt of the sulfonated monoglyceride of cocoanut fatty acids, sorbitan sesquioleate , lauryl trimethyl ammonium chloride, octadecyl trimethyl ammonium chloride, polyethylene glycol lauryl ether, polyethylene glycol esters of fatty acids and rosin acids, e.g. Ethofat 7 and 1j5, sodium N-methyl-N-oleyl taurate, Turkey Red Oil, sodium dibutyl naphthalene sulfonate, sodium lignin sulfonate, polyethylene glycol stearate, sodium dodecylbenzene sulfonate, tertiary dodecyl polyetbylene^ glycol thioether (Nonionic 218), long chain ethylene oxide-propylene oxide condensation products, e.g. Pluronic 61 (molecular weight 1000), polyethylene glycol ester of tall oil acids, sodium octyl phenoxyethoxyethyl sulfate, tris (polyoxyethylene) sorbitan monostearate (Tween 60), and sodium dibexyl sulfosuccinate.

The parasitic nematode test was carried out using Meloidogyne spp. with a 10 day contact test carried out in a water-agar medium in the presence of tomato roots at room temperature.

In Table 1 the same scale is employed with 0 indicating no control (severe knotting) and 10 indicating complete control. The compounds tested had the formula and R, were identical Le A 12050 - 10 - It is clear from the table that the particular grouping chosen for is critical in order to obtain nematocidal activity. Of the compounds tested S, S-diisopropyl -2-methoxy-vinylphospbonodithioate (Compound 7375) had by far the best activity as a nematocide while S, S-dipropyl-2-t-butoxyvinyl-phosphonodithioate (Compound 7959) was next best.

Le A 120 0 - 11 - When the nematocides of the present invention are applied after emergence of the desired crop plants they, of course, should be used in an amount effective to kill the nematodes but insufficient to act as a herbicide.

Le A 12050 - 12 - 32054/3 ^

Claims (1)

1. CLAIMS A compound having the formula where is isopropyl or and and are independently each an of 1 to 4 carbon A compound according to Claim 1 wherein and are both compositions comprising a todicidally effective amount of a compound having the formula I in Claim A process of killing nematodes comprising applying to the nematode habitat a nematodicidally effective amount of a compound having the formula 1 in Claim For the Applicants AND PARTNERS HE insufficientOCRQuality