Trifluoroacetic acid → 3-Piperidin-4-yl-7-trifluoromethyl-benzo[b]thiophene-2-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a room temperature solution of 4-(3-hydroxy-2-methoxycarbonyl-7-trifluoromethyl-2,3-dihydro-benzo[b]thiophen-3-yl)-piperidine-1-carboxylic acid tert-butyl ester (6.00 g, 13.0 mmol) in DCM (30 mL) was added TFA (30 mL) causing rapid gas evolution. After 5 min, the reaction was stirred at 40° C. for 5.5 h. After cooling to room temperature, the reaction was poured into 20% aqueous potassium carbonate (400 mL) and extracted with DCM (2×200 mL). The combined extracts were dried over magnesium sulfate, filtered, and the solvent removed to give a thick oil. After drying under high vacuum 4.37 g (98%) of the desired product was obtained as a white foam.

Provenance & Evidence