Methanesulfonic Acid → Ethyl 3-difluoromethyl-1-methyl-4-pyrazole carboxylate

Participants

Reaction Conditions

Reaction Steps

To 20.4 g of ethyl 5-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate (iso-DFPE) was added 11.3 g of dimethyl phosphite and 0.82 g of methane sulfonic acid. The mixture was heated to 170° C. and stirred for 7 hours. The solution was cooled and distilled to recover recycled trimethyl phosphate and 0.9 g of starting ethyl 5-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate (iso-DFPE). The remaining solution was added to 50 g of cold water. The solution was allowed to stir for 30 min. The precipitating solid was filtered and dried to give 14.1 g of product.

Provenance & Evidence