Processo para preparar ésteres de 1, 3-di-substituído pirazol carboxílicos, e, uso dos ésteres 1, 3-di-substituído pirazol carboxílicos

摘要

A process for preparing 1,3-disubstituted pyrazolecarboxylic esters of the formula (I) where X, Y, Z=hydrogen or halogen and R1=C1-C6-alkyl, by metering an enol ether of the formula III where R2 is C1-C6-alkyl at from (−41) to (−80)° C. into an alkyl hydrazine of the formula II H2N—NH-lower alkyl  (II).