4-[(4-Methylphenyl)sulfonyl]piperidine hydrochloride

144464-66-4

3470-46-0

Methyl 5-oxo-5,6,7,8-tetrahydronaphthalene-2-carboxylate (320 mg, 1.57 mmol) was used as a raw material and dissolved in a solvent mixture of 6 mL of methanol and 3 mL of water. Subsequently, lithium hydroxide (331 mg, 7.88 mmol) was added. The reaction mixture was stirred at room temperature for 1 h. The progress of the reaction was monitored by thin-layer chromatography (TLC), and after confirming that the reaction was complete, the pH of the reaction solution was adjusted to 5 with 1 N hydrochloric acid solution.The reaction solution was concentrated by rotary evaporation and extracted with ethyl acetate (50 mL × 2). The ethyl acetate extracts were combined and the solvent was removed by rotary evaporation to afford the white solid product 5-oxo-5,6,7,8-tetrahydronaphthalene-2-carboxylic acid (310 mg, 100% yield).