Hydrochloric Acid → 5-bromo-2-(2-hydroxypropan-2-yl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxamide

Participants

Reaction Steps

A solution of ethyl 5-bromo-8-carbamoyl-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylate (Intermediate 46-1, 2 g, 5.48 mmol) in THF (100 mL) cooled in an ice bath was treated with methyllithium (1.6 M in diethyl ether, 17.11 mL, 27.4 mmol). After 1 h, the mixture was treated slowly with a mixture of 1 M hydrochloric acid (20 mL) and ice (20 g). The organic layer was separated, and the aqueous layer was extracted twice with DCM. The combined organic phases were washed with water and brine, dried and concentrated. The residue was triturated with DCM to provide 5-bromo-2-(2-hydroxypropan-2-yl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxamide as a light yellow solid (1.72 g, 89%). 1H NMR (400 MHz, methanol-d4) δ7.38 (1 H, d, J=8.14 Hz), 7.16 (1 H, d, J=8.14 Hz), 3.37-3.45 (1 H, m), 2.90-2.97 (1 H, m), 2.79-2.89 (1 H, m), 2.54-2.64 (1 H, m), 2.20-2.28 (1 H, m), 1.80-1.90 (1 H, m, J=11.94, 11.94, 4.95, 2.20 Hz), 1.41-1.53 (1 H, m, J=12.43, 12.43, 12.32, 5.28 Hz), 1.30 (6 H, s). Mass spectrum m/z 351, 353 (M+H)+.

Provenance & Evidence