Diethyl Ether → 5-Bromo-6-fluoro-2-(2-hydroxypropan-2-yl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxamide

Participants

Reaction Conditions

Reaction Steps

A solution of ethyl 5-bromo-8-carbamoyl-6-fluoro-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylate (10.0 g, 26.1 mmol) in THF (200 mL) at −78° C. was treated dropwise over 30 min with 1.6 M methyllithium in ether (49 mL, 78 mmol). The mixture was stirred at −78° C. for 45 min, then was treated with additional methyllithium solution (33 mL) over 25 min. The mixture was stirred at −78° C. for an additional 90 min, then was treated with saturated aqueous NH4Cl and warmed to room temperature. The mixture was diluted with EtOAc and washed sequentially with water and brine. The aqueous layers were extracted with EtOAc. The combined organic layers were dried and concentrated. The residue was dissolved in EtOAc (about 100 mL) and filtered through a pad of CELITE® topped with a pad of silica gel, washing further with EtOAc (about 1000 mL). Concentration of the filtrate gave racemic 5-bromo-6-fluoro-2-(2-hydroxypropan-2-yl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxamide as a pale yellow solid (9.24 g, 96% yield). Mass spectrum m/z 369, 371 (M+H)+.

Provenance & Evidence