Method for the production of trioxime derivatives

The present invention relates to a process for preparing trioxime derivatives of the formula I in which the substituents R1 and R2 are identical or different and each is cyano, alkyl, haloalkyl or cycloalkyl, and R3 and R4 are identical or different and each is alkyl, haloalkyl, cycloalkyl, alkylcarbonyl or arylalkyl, 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 H2N-OR3' IV in which R3' is hydrogen or a group R3 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.