Sodium Hydroxide → 5-(4-Fluorophenyl)-1-(6-methoxy-3-pyridyl)pyrazole-3-carboxylic acid

Participants

Reaction Steps

Aqueous 1N sodium hydroxide (1.2 L) was added to 5-(4-fluorophenyl)-1-(6-methoxy-3-pyridyl)pyrazole-3-carboxylic acid ethyl ester (164 g) in methanol (1.6 L), and the resultant mixture was stirred at room temperature for 5 hours. The reaction solvent was removed under reduced pressure, and the residue was partitioned between water and diethyl ether. The aqueous layer was adjusted at pH 2 through addition of aqueous 1N hydrochloric acid (1.5 L), and the precipitated crystals were dissolved in chloroform. The resultant solution was partitioned by use of saturated brine, and the organic layer was dried over sodium sulfate anhydrate, followed by filtration. The solvent was evaporated under reduced pressure, and the precipitated crystals from diethyl ether were recovered by filtration, to thereby give the title compound (132.0 g, 88%).

Provenance & Evidence