Processo para preparação de pirazóis, uso e processo para a alquilação regiosseletiva

摘要

The present invention relates to a process for the preparation of compounds of formula I wherein R1 is C1-C4haloalkyl; R2 is C1-C6alkyl and R3 is methyl or ethyl, by reaction of compounds of formula II wherein the substituents are as defined for formula I, with compounds of formula III wherein R3 is as defined for formula I and n is 0 or 1.