Triphenylphosphine → 4-bromo-7-(3,3-dimethyl-2-oxopyrrolidin-1-yl)-9H-carbazole-1-carboxamide

Beteiligte Stoffe

Reaktionsschritte

A solution of 4-bromo-7-(4-hydroxy-2,2-dimethylbutanamido)-9H-carbazole-1-carboxamide (Intermediate 58-1, 89 mg, 0.213 mmol), diethyl azodicarboxylate (0.051 mL, 0.319 mmol) and triphenylphosphine (84 mg, 0.319 mmol) in THF (1 mL) was stirred at rt for 1 h. More diethyl azodicarboxylate (0.051 mL, 0.319 mmol) and triphenylphosphine (84 mg, 0.319 mmol) were added, and these additions repeated again after 1 h more. The mixture was diluted with DCM, washed with NaHCO3 (aq) and water, and dried and concentrated. The residue was purified by column chromatography (eluting with a gradient from DCM to 90:9:1 DCM-methanol-28% aqueous ammonium hydroxide), then by preparative HPLC. The appropriate effluent fractions were made basic with 1 M aqueous sodium hydroxide and extracted twice with DCM. The combined organic phases were washed with water, dried and concentrated to provide 4-bromo-7-(3,3-dimethyl-2-oxopyrrolidin-1-yl)-9H-carbazole-1-carboxamide as a yellow solid (44 mg, 52%). 1H NMR (400 MHz, methanol-d4) δ 8.66 (1H, d, J=8.58 Hz), 7.94 (1H, d, J=1.54 Hz), 7.73 (1H, d, J=8.36 Hz), 7.55 (1H, dd, J=8.80, 1.98 Hz), 7.39 (1H, d, J=8.14 Hz), 3.97 (2H, t, J=6.93 Hz), 2.11 (2H, t, J=6.93 Hz), 1.28 (6H, s). Mass spectrum m/z 400, 402 (M+H)+.

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