GB1138347A - Carbamyl hydroxamate pesticides - Google Patents

Abstract

1,138,347. Carbamyl hydroxamates. E. I. DU PONT DE NEMOURS & CO. 21 Dec., 1965, No. 54148/65. Heading C2C. [Also in Divisions A5 and C3] The invention relates to O-carbamyl hydroxamates of the general formula in which R 1 is alkyl of 1 to 12 carbon atoms, haloalkyl of 1 to 12 carbon atoms and 1 to 10 halogen atoms, cycloalkyl of 3 to 10 carbon atoms, benzyl, chlorobenzyl, 1-naphthyl, 2- naphthyl, phenyl, where X is fluorine, chlorine, bromine, alkyl of 1 to 4 carbon atoms, alkenyl of 2 to 4 carbon atoms, cyclohexyl, alkoxy of 1 to 4 carbon atoms, methylthio, dimethyl amino, nitro, cyano, nitroso or trifluoromethyl; Y is H, fluorine, chlorine, bromine, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms or nitro; Z is chlorine, bromine or alkyl of 1 to 4 carbon atoms; and n is 0, 1 or 2; R 2 and R 3 , which can be the same or different, are hydrogen or methyl; and Q is alkylthio of 1 to 12 carbon atoms, phenylthio, p-chlorophenylthio, benzylthio or p-chlorobenzylthio, with the proviso that Q is alkylthio of 1 to 3 carbon atoms when R 1 contains more than 5 carbon atoms. Compounds claimed per se are methyl O - (methylcarbamyl) - p - chloro - thiobenzohydroxamate, methyl O - (dimethylcarbamyl)- thiolacetohydroxamate, sec. - butyl O - (methylcarbamyl) - thiolacetohydroxamate, methyl O- (methylcarbamyl) - p - fluorothiolbenzohydroxamate, methyl-O- (methylcarbamyl)-p-bromothiolbenzohydroxamate, methyl O - (methylcarbamyl) - thiolbutyrohydroxamate, isopropyl O - (methylcarbamyl) - thiodiisobutyrohydroxamate. The O-carbamyl-hydroxamate esters may be prepared by treating a hydroxamate or thiolhydroxamate ester with sodium hydride in tetrahydrofuran, adding the resulting sodium salt to a solution of phosgene, and then treating the chloroformate intermediate with two equivalents of ammonia. The O-methylcarbamyl hydroxamate esters may be prepared by treating a hydroxamate or thiolhydroxamate ester with methyl isocyanate with a small amount of 1,4 - diazabicyclo - [2,2,2] - octane present as a catalyst. The dimethyl compound is prepared by reacting the sodium salt of a thiol hydroxamate ester with dimethylcarbamyl chloride. The thiolhydroxamate ester starting material may be obtained by reacting an imino ether (which may be prepared by reacting a nitrile of formula R 1 CN with a mercaptan of formula QH) with hydroxylamine. They may also be prepared by reacting a hydroxamyl chloride of formula R 1 C(Q)NOH with an alkali metal salt of an alkyl mercaptan of formula QH where Q is alkylthio of 1-12 carbon atoms.