Bromide ion → 1-[4-Chloro-2-fluoro-5-(2-propyn-1-yloxy)phenyl]-3,5-dimethyl-4-nitro-1h-pyrazole

Participants

Reaction Conditions

Reaction Steps

A mixture of 1-(2-fluoro-4-chloro-5-hydroxyphenyl)-3,5-dimethyl-4-nitropyrazole (28.7 g), propargy bromide (13.1 g), anhydrous potassium carbonate (15.2 g) and acetonitrile (200 ml) was stirred at 60° C. for 2 hours. After cooling, the reaction mixture was filtered through a filter to remove crystalline solid matters and the filtrate was concentrated to a small volume under reduced pressure. The concentrated solution was admixed with toluene and water to form two layers. The toluene layer formed (the extract) was separated, washed with water and then dried over anhydrous sodium sulfate. Removal of the solvent by distillation in vacuo gave the titled compound (31.2 g) as a pale yellow crystalline solid. Recrystallization of this solid from a mixture of n-hexane/ethyl acetate yielded a white crystalline solid. m.p. 125°-126.5° C.

Provenance & Evidence