Process for the preparation of N-substituted pyrazoles.

摘要

Process for the preparation of N-substituted pyrazoles of the general formula I in which R<1> is C1- to C12-alkyl or C7- to C20-phenylalkyl and R<2>, R<3> and R<4> independently of one another are hydrogen, C1- to C12-alkyl, phenyl, C7- to C20-alkylphenyl or C7- to C20-phenylalkyl, by reacting pyrazoles of the general formula II in which R<2>, R<3> and R<4> have the abovementioned meanings, with compounds of the general formula III R<1> - O - R<5> (III> in which R<1> has the abovementioned meanings and R<5> is hydrogen or R<1>, in the presence of a catalyst at temperatures from 200 to 550@C and pressures from 0.001 to 50 bar, using a heterogeneous catalyst as the catalyst.