Methoxy-substituted cyanophenyl ester derivatives of phosphorus acids as insecticidal agents

#This invention is directed to certain novel phosphorus-containing compounds, a process for preparing said compounds, and their method of use as pest-controlling agents.

#The novel compounds are the methoxy-substituted cyanophenyl ester derivatives of phosphinic, phosphonic, phosphoric, thiophosphinic, thiophosphonic, and thiophosphoric acids, which compound may be represented generically by the following general formula: ##STR2## wherein R and R.sup.1 are independently selected from the group consisting of lower alkyl, chloro-substituted lower alkyl, lower alkoxy, phenyl, phenoxy, and lower dialkylamido and X is selected from the group consisting of oxygen and sulfur. The lower alkyl, chloro-substituted lower alkyl, and lower alkoxy groups represented by R and R.sup.1, will contain up to 8 carbon atoms, either in branched or straight chains. The alkyl portions of the dialkylamido radicals will contain from 1 to 3 carbon atoms.

#The novel compounds of the present invention are prepared according to the following general reaction: ##STR3## WHEREIN Hal stand for a halogen selected from chlorine, iodine, and bromine, preferably chlorine, "acceptor" stands for a hydrogen halide acceptor such as a tertiary amine or the like, and R, R.sup.1, and X are as defined hereinbefore. Reaction is preferably carried out at or slightly above room temperature, for example, at a temperature between about 20.degree. and 80.degree. C., although the reaction is possible at all temperatures between about 0.degree. and 100.degree. C. The hydrogen halide acceptor is useful in preventing possible side reactions between the product and the halogen acid generated in the reaction. In a preferred process for making the novel compounds of the invention, the reaction is preferably carried out in the presence of an inert organic solvent such as benzene, dioxime, toluene, and xylene. By a variation of the process, sodium carbonate, or the like, may be used in place of the hydrogen halide acceptor to remove acid from the reaction matrix.

#The preparation of the compounds of this invention is illustrated by the following non-limiting examples, many variations of which will occur to those skilled in the art without departing from the spirit or scope thereof:

#To 7.5 grams of vanillin nitrile, 6.0 grams of triethylamine and 75 ml. benzene maintained at a temperature of 20.degree.-30.degree. C. was added 11.4 grams of (C.sub.4 H(O).sub. 2 P(O)Cl. The reaction matrix was allowed to stir for 48 hours, after which time it was filtered and the filtrate was washed. The filtrate was then concentrated by evaporation to 60.degree. C. at 1 mm. Hg to yield 12.6 grams (72% of theoretical yield) of 0,0-dibutyl-0-(2-methoxy-4-cyanophenyl) phosphate, having an index of refraction N.sub.D.sup.25 = 1.5331.

#To 8.7 grams of (C.sub.2 H.sub.5 O).sub.2 P(O)Cl and 20 ml. of benzene was added dropwise, at 25.degree. C., 7.5 grams of vanillin nitrile and 6.0 grams of triethylamine and 75 ml. of benzene. After stirring overnight at room temperature, the reaction mixture was heated to 60.degree. C. for 1 hour, cooled, filtered, and the filtrate was concentrated by evaporation to 60.degree. C. at 1 mm. Hg. The concentrate consisted of 14.0 grams (97% of theoretical yield) of 0,0-diethyl-0-(2-methoxy-4-cyanophenyl) phosphate, having an index of refraction N.sub.D.sup.25 = 1.4991. By analysis, the product consisted of 10.9% P, 4.1% N, and 0.3% Cl, compared to the theoretical values of 10.9% P, 4.1% N, and 0.0% Cl for the compound of the formula shown immediately above.