Hydrochloric Acid → 2-(Hydroxymethyl)benzo[b]thiophene

Participants

Reaction Conditions

Reaction Steps

Benzothiophene (5.0 g, 37.3 mmol) in anhydrous THF (100 ml) stirring at −20° C. was treated with n-butyllithium (34 ml, 1.6 M, 55.8 mmol) and stirred for 1 hour. The mixture was cooled to −78° C. and treated with paraformaldehyde (7.8 g, 261 mmol) in four portions. The mixture was allowed to slowly warm to room temperature with stirring overnight. The mixture was treated with 2N HCl (100 ml) and extracted with diethyl ether (2×100 ml). The organic phases were combined, dried over NaSO4, filtered, and the filtrate concentrated under reduced pressure. The residue was crystallized from DCM/hexanes to provide the title compound. 1H NMR (300 MHz, CDCl3) δ 4.94 (s, 2H) 7.23 (s, 1H) 7.33 (m, 3H) 7.74 (m, 1H); (ESI) m/z 165 (M+H)+.

Provenance & Evidence