| 摘要 |
PCT No. PCT/EP96/00790 Sec. 371 Date Aug. 20, 1997 Sec. 102(e) Date Aug. 20, 1997 PCT Filed Feb. 27, 1996 PCT Pub. No. WO96/27589 PCT Pub. Date Sep. 12, 1996A process for the preparation of an N-alkyl- or N-phenylalkyl-substituted pyrazole I by reacting the corresponding N-unsubstituted pyrazole II with an alcohol III of the formula R1-OH where R1 is the same alkyl or phenylalkyl group to be added to the unsubstituted nitrogen group -NH- of the pyrazole reactant. Both of the reactants, i.e. the pyrazole II and alcohol III compounds, are catalytically reacted in the liquid phase in a molar ratio of from 0.001:1 to 1:1, at temperatures of 50 DEG -400 DEG C. and under a subatmosheric pressure of from 0.8 bar up to a superatmospheric pressure of 250 bar. The catalyst required for this liquid phase reaction is selected as being at least one or more non-heterogeneous acid catalysts, their alkyl esters or their acid anhydrides. |
