METHOD FOR THE PRODUCTION OF HALOGEN-SUBSTITUTED 2-(AMINOMETHYLIDENE)-3- OXOBUTYRIC ACID ESTERS

摘要

The present invention relates to a method for producing 2- (aminomethylidene)-4,4dihalo-3-oxobutyric acid esters of the formula (I), where R1, R2, R3 are C1-C6-alkyl, C1-C6-haloalkyl, C2-C6-alkenyl, C3-C10-cycloalkyl or benzyl and/or R2 together with R3 and the nitrogen atom, to which both radicals are bound, are a heterocyclic radical, wherein a corresponding 3-aminoacrylic acid ester is reacted with a halogen-substituted acetyl fluoride in the presence of at least one alkali or earth alkali metal fluoride. The invention also relates to the further reaction of halogen-substituted 2-(aminomethylidene)-3-oxobutyric acid esters of the formula (1) into halomethyl-substituted pyrazole-4-ylcarboxylic acids and the esters thereof.