Acetyl chloride → 3-(1-Acetyl-piperidin-4-yl)-7-trifluoromethyl-benzo[b]thiophene-2-carboxylic acid methyl ester

Participants

Reaction Steps

To a room temperature solution of 3-piperidin-4-yl-7-trifluoromethyl-benzo[b]thiophene-2-carboxylic acid methyl ester (4.37 g, 12.7 mmol), triethylamine (2.70 mL. 19.4 mmol), and anhydrous THF (80 mL) under nitrogen was added acetyl chloride (1.10 mL, 15.5 mmol) in one portion and the reaction stirred at room temperature overnight. The reaction was diluted with ethyl acetate (300 mL) and washed with water (150 mL) and brine (150 mL) successively. The organic layer was dried over magnesium sulfate, filtered, and the solvent removed. The residue was chromatographed on silica, eluting with 10% methanol/ethyl acetate, to afford 4.28 g (88%) of the desired product as a white solid, mp: 155.2° C.

Provenance & Evidence