Trifluoroacetic acid → HCID 45138929, compound

Participants

Reaction Steps

A mixture of 5,7-diBOC-2,10-difluoro-6-hydroxyindolo[2,3-b]carbazole (406.8 mg, 0.8 mmol), 2-(dimethylamino)ethyl chloride hydrochloride (126.8 mg, 0.88 mmol) and K2CO3 (10 equivalents) in 4A-molecular-sieve-dried acetone (40 mL) was magnetically stirred and heated to reflux under Ar. After the reaction was complete, it was cooled to room temperature. The inorganic salt was removed by filtration and washed with a small quantity of acetone. The combined acetone solution was concentrated on a rotavapor and dried under vacuum pump. The crude product was purified by flash chromatography. The resultant product 2-(2,10-difluoro-5,7-diBOC-indolo[2,3-b]carbazol-6-yloxy)-N,N-dimethylethanamine was dissolved in CH2Cl2 (40 mL), and trifluoroacetic acid (˜40 equivalents) was added. The reaction was stirred at room temperature overnight, concentrated, and dried under vacuum pump. The crude compound was dissolved in ethyl acetate (40 mL), washed with saturated NaHCO3 solution, dried under Na2SO4, concentrated, and flash chromatography to provide the desired product 2-(2,10-difluoro-5,7-dihydroindolo[2,3-b]carbazol-6-yloxy)-N,N-dimethylethanamine (195.9 mg, 65%). 1 H-NMR (400 MHz, DMSO-d6) δ ppm 11.40 (s, 2 H), 8.56 (s, 1 H), 7.87 (dd, J=9.2, 2.4 Hz, 2 H), 7.44 (dd, J=8.4, 4.4 Hz, 2 H), 7.20-7.11 (m, 2 H), 4.30 (t, J=5.8 Hz, 2 H), 2.72 (t, J=5.8 Hz, 2 H), 2.32 (s, 6 H); MS (ESI) m/z 378.1 (M−H)−; MS (ESI) m/z 380.1 (M+H)+

Provenance & Evidence