Sodium Hydroxide → 1-(4-tert-Butoxyethoxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid

Participants

Reaction Steps

To a solution of 1-(4-tert-butoxyethoxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (870 mg) in methanol (30 ml) was added 4 N aqueous solution of sodium hydroxide (10 ml), and stirred at room temperature overnight. After completion of the reaction, the organic solvent was evaporated in vacuo, then water and diethyl ether were added thereto, and the aqueous layer was separated. To the aqueous layer was added concentrated hydrochloric acid under ice-cooling to adjust the layer to pH 5, and extracted with chloroform. The organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated in vacuo. The obtained residue was purified with silica gel chromatography (chloroform/methanol), isopropylether was added thereto, the precipitated solid was collected by filtration, and heat-dried at 60° C. in vacuo to give the titled compound (363 mg) as a white solid.

Provenance & Evidence