Patent ID: 6906223

Claim:
A process for preparing trioxime derivatives of the formula I in which the substituents R 1 and R 2 are identical or different and each is cyano, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl or C 3 -C 6 -cycloalkyl, and R 3 and R 4 are identical or different and each is C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 3 -C 6 -cycloalkyl, C 1 -C 4 -alkylcarbonyl or aryl-C 1 -C 4 -alkyl, by the following reaction steps in water without isolation of the intermediates: A) nitrosation of 1,3-diketones of the formula II to give monooximes of the formula III, B) oximation of III with hydroxylamine derivatives of the formula IV H 2 N—OR 3′ IV in which R 3′ is hydrogen or a group R 3 , or acid addition salts thereof, to give bisoximes of the formula V, C) alkylation of V with alkylating agents or acylation of V with acylating agents to give compounds of the formula VI and D) subsequent oximation of VI with hydroxylamine to give compounds of the formula I.