Hydrochloric Acid → 5-[3-(4-benzo[b]thiophen-4-yl-piperazin-1-yl)propoxy]-1-methyl-1H-pyrazole-3-carboxylic acid

Participants

Reaction Steps

A 6N aqueous sodium hydroxide solution (2 ml) was added to an ethanol solution (10 ml) of methyl 5-[3-(4-benzo[b]thiophen-4-yl-piperazin-1-yl)propoxy]-1-methyl-1H-pyrazole-3-carboxylate (1.62 g, 3.9 mmol) and the mixture was stirred at room temperature for 4 days. Then, 6N hydrochloric acid (2 ml) was added to the reaction solution under ice cooling and the solution mixture was stirred. Dichloromethane was added to the reaction solution and the precipitate was obtained by filtration. The filtrate was separated and the organic phase was concentrated under reduced pressure. The filter cake and the residue were combined, washed with water and dried to obtain 5-[3-(4-benzo[b]thiophen-4-yl-piperazin-1-yl)propoxy]-1-methyl-1H-pyrazole-3-carboxylic acid (1.53 g) as white powder.

Provenance & Evidence