GB1263138A - Episulphides of unsaturated acids and alcohols, derivatives thereof and the use thereof as pesticides - Google Patents

Abstract

1,263,138. Episulphides of unsaturated acids and alcohols; derivatives thereof. F. HOFFMANN-LA ROCHE & CO. A.G. 25 Sept., 1969 [27 Sept., 1968], No. 47141/69. Heading C2C. Novel episulphides of the formula in which A and B are hydrogen or together represent a double bond or a sulphur bridge, R is hydrogen or C 1-6 alkyl, R<SP>5</SP> is hydrogen or methyl, Y is cyano, carboxyl, C 1-6 alkoxycarbonyl, phenyloxycarbonyl or benzyloxycarbonyl (in which either phenyl moiety may be substituted by hydroxy, C 1-6 alkyl, C 1-6 alkoxy or halogen), a group -CONR<SP>2</SP>R<SP>3</SP> (in which R<SP>2</SP> and R<SP>3</SP> are each hydrogen, C 1-6 alkyl or together complete a 5- or 6-membered heterocycle which may contain O, S or N as an additional hetero atom), a group -CH 2 OR<SP>4</SP>, in which R<SP>4</SP> is hydrogen, C 1-6 alkyl, C 1-6 alkanoyl, C 6-10 aroyl, benzoyl substituted by C 1-6 alkyl, amino-C 1-6 alkyl, or a phenyl or benzyl group (which phenyl or benzyl group may be substituted by C 1-6 alkyl, C 1-6 alkoxy, methylenedioxy, C 1-6 alkoxycarbonyl, C 1-6 -alkanoyl, C 6-10 aroyl, C 1-6 alkylbenzoyl, phenyl-C 1-6 -alkyl or halogen), and n is 0 or 1, are prepared (a) by reacting a ketone of the formula with a phosphonate of the formula in the presence of a base and an organic solvent, where R<SP>6</SP> is cyano, -COOR<SP>1</SP> or -CONR<SP>1</SP>R<SP>3</SP>, in which COOR<SP>1</SP> is an esterified carboxyl value of Y above, and R<SP>7</SP> and R<SP>8</SP> are C 1-6 alkoxy or phenoxy optionally substituted by C 1-6 alkoxy, nitro or halogen, or (b) episulphidizing a compound of the formula in which A<SP>1</SP> is hydrogen or hydroxy, B<SP>1</SP> is hydrogen or halogen or A<SP>1</SP> and B<SP>1</SP> together represent a double bond or a sulphur bridge, D is hydroxy and E is halogen or D and E together represent an oxygen bridge, and in either case, if desired, hydrolysing any ester formed. Episulphidizing agents for use in (b) include thiourea, thiocyanates, thiobarbituric acid, thioamides and thiosulphates. If Compound IV is a halohydrin and thiourea is used, an isothiouronium salt is obtained which yields the epithio compound on treatment with a base. The final products can be converted to other values of Y by conventional methods, e.g. the free acid, via the acid halide, yields the amides or esters, the alcohol via the metal salts to the ethers or acylated alcohols. Examples describe the preparation of epithio derivatives of 3,7,11-alkyl 2,6,10-dodecatrienyl and tridecatrienyl compounds. 10,11-Epoxy-3,7,11-trimethyl-1-[(p-benzylphenyl)oxy]2-cis/trans,6-cis-dodecadiene is obtained by reacting 2-cis/trans-6-cis-farnesyl bromide with p-benzylphenol to form p-benzylphenyl 3,7,11-trimethyl-2-cis/trans,6-cis,10-dodecatrienyl ether which is halogenated with N-bromosuccinimide to obtain 3-bromo-2,6,10-trimethyl-12- [(p-benzylphenyl)oxy]-6-cis,10-cis/trans-dodecadien-2-ol which yields the required dodecadiene on treatment with NaOMe. 10,11-Epoxy-3,7,10,11- tetramethyl-dodeca-2,6-dienoic acid ethyl ester is obtained by epoxidizing 6,9,10-trimethylundeca- 5,9-dien-2-one to 9,10-epoxy-6,9,10-trimethylundeca-5-en-2-one which is condensed with diethyl phosphoniacetic acid ethyl ester. 9,10- Epithio-6,10-dimethyl-undec-5-trans-en-2-one is obtained by treating the corresponding 9,10 epoxy ketone with thiourea and Na 2 CO 3 . 9,10- Epithio - 6,9,10 - trimethylundec - 5 - cis/transen-2-one is obtained similarly. 10,11-Epoxy- 3,7,11 - trimethyldodeca - 2 - cis/trans, 6 - transdienenitrile is obtained by condensing 9,10- epoxy - 6,10 - dimethylundec - 5 - trans - en - 2- one with diethyl phosphonoacetonitrile. The novel episulphides upset the hormone balance of pests such as insects and are used in conventional forms to protect foodstuffs, textiles and plants from such pests.