Hydrochloric Acid → HCID 67493549, compound

Participants

Reaction Steps

In a flask were 2-fluorophenylhydrazine hydrochloride (12.2 g, 75 mmol), diethylacetylene dicarboxylate (12.8 g, 75 mmol), potassium carbonate (20.7 g, 150 mmol), and ethanol (200 ml) placed and the resulting slurry heated at reflux for 5 hours. The mixture was cooled to room temp, diluted with water (400 ml) and acidified carefully with 2M hydrochloric acid. The mixture was stirred for 2 h then the resulting suspended solid collected by filtration, washed with water (3×50 ml) and dried in vacuo giving 11.4 g of 5-Chloro-1-(2-fluoro-phenyl)-1H-pyrazole-3-carboxylic acid ethyl ester [U1]. 1H NMR (300 MHz., DMSO): δ 1.29 (3H,t), 4.25 (2H,q), 5.92 (1H,s), 7.34-7.60 84H,m), 11.90 (1H,s,br). LCMS (Method A): RT=1.75 min, (M+H)+=251.

Provenance & Evidence