Patent ID: 7714144
Filing Date: 2010-05-11
Classification: B01J,C07D

Abstract:
1. Process for preparing 5-fluoro-1,3-dialkyl-1H-pyrazole-4-carbonyl fluorides of the formula (I) in which R comprising: converting 5-chloro-1,3-dialkyl-1H-pyrazole-4-carbonyl chlorides of the formula (II) in which R in the presence of potassium fluoride, in the presence of a phase transfer catalyst selected from (A) a quaternary phosphonium compound of the formula (III) or (B) an amidophosphonium salt of the formula (IV) or (C) a compound of the formula (V) or (D) a hexaalkylguanidinium salt of the formula (VI) in the presence of a polyether of the formula (VII) and in the presence of catalytic amounts of a protic compound selected from the group consisting of sulpholane, dimethyl sulphoxide (DMSO), dimethylacetamide, dimethylformamide (DMF), N-methylpyrrolidone (NMP), 1,3-dimethylimidazolinone, HF, water, dichloromethane, chloroform, dichloroethane, trichloroethane, ketones nitriles, and amides.