Water → HCID 66606813, compound

Participants

Reaction Steps

Step 1 A solution of potassium tert-butoxide (3.40 g, 30.3 mmol) in THF (249 mL) at 0° C. was treated with methyltriphenylphosphonium bromide (8.79 g, 24.60 mmol), forming a bright yellow suspension. After 1 h, 4-bromo-7-formyl-9H-carbazole-1-carboxamide (prepared according to the procedure of Step 1 of Example 41-1, 4 g, 9.46 mmol) was added, and the resulting suspension was warmed to rt and stirred for 3 h. Water was added and the mixture was extracted with EtOAc. The organic phase was washed with brine, dried and concentrated. The residue was purified by column chromatography (eluting with a gradient from 70:30 hexane-EtOAc to EtOAc). The crude material was suspended in methanol, and the precipitate was collected by filtration and dried. The filtrate was concentrated to provide additional solid which was collected by filtration, dried and combined with the first crop to provide 4-bromo-7-vinyl-9H-carbazole-1-carboxamide as a light brown solid (1.66 g, ca. 90% purity, 50%). 1H NMR (400 MHz, DMSO-d6) δ 11.68 (1H, s), 8.52 (1H, d, J=8.3 Hz), 8.06-8.29 (1H, m), 7.79-7.88 (2H, m), 7.58 (1H, br. s.), 7.35-7.45 (2H, m), 6.78-6.98 (1H, m), 5.88 (1H, d, J=17.6 Hz), 5.32 (1H, d). Mass spectrum m/z 344, 346 (M+H)+.

Provenance & Evidence