PROCESS FOR THE STEREOSELECTIVE PREPARATION OF A PYRAZOLE CARBOXAMIDE

摘要

The present invention relates to a process for the enantioselective preparation of 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid ((1S,4R)-9-dichloromethylene-1,2,3,4-tetrahydro-1,4-methano-naphthalen-5-yl)-amide of formula Ib.;

主权项

1. A process for the enantioselective preparation of 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid ((1S,4R)-9-dichloromethylene-1,2,3,4-tetrahydro-1,4-methano-naphthalen-5-yl)-amide of formula Ib which process comprises a) reducing a compound of formula II with an enantioselective reagent to a compound of formula IIIe b) dehydrating the compound of formula IIIe in the presence of an acid to the compound of formula IVa c) reacting the compound of formula IVa with hydroxylamine to the compound of formula Va and d) acylating the oxime oxygen of the compound of formula Va in the presence of a solvent and an acylating agent and finally reacting the obtained product with the compound of formula VIor
e) reacting the compound of formula V with an excess of the compound of formula VI.