1,2-Dichloroethane → 3-bromo-7-(4-methylpiperazine-1-carbonyl)-9H-carbazole-1-carboxamide

Participants

Reaction Steps

To a suspension of 6-bromo-8-carbamoyl-9H-carbazole-2-carboxylic acid (8.47 g, 8.64 mmol), EDC (1.657 g, 8.64 mmol), and 1-hydroxybenzotriazole hydrate (1.324 g, 8.64 mmol) in THF/CH2Cl2 (5/1) (40 mL) was added 1-methylpiperazine (3.84 mL, 34.6 mmol). The reaction mixture turned into a dark pink suspension. The reaction mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated and partitioned between ethyl acetate and water/sat. NaHCO3. The aqueous phase was re-extracted with ethyl acetate. The organic phase was washed with brine, dried over MgSO4 and concentrated to afford the crude product as a dark pink solid, which was purified by silica gel column chromatography (CH2Cl2/2M NH3 in MeOH=100/5-100/7). The product obtained was suspended in ethyl acetate and colorless solid was collected by filtration and air-dried to give 1.78 G of 3-bromo-7-(4-methylpiperazine-1-carbonyl)-9H-carbazole-1-carboxamide. MS (ESI) m/z 415.1 (M+H). 1H NMR (DMSO-d6) δ ppm 11.68 (s, 1H) 8.60 (d, J=1.76 Hz, 1H) 8.28 (br. s., 1H 8.24 (d, J=8.13 Hz, 1H), 8.16 (d, J=1.76 Hz, 1H) 7.75 (s, 1H) 7.64 (br. s., 1H) 7.14-7.22 (m, 1H) 3.34-3.75 (m, 4H) 2.24-2.44 (m, 4H) 2.20 (s, 3H).

Provenance & Evidence