Hydrochloric Acid → 2,3-dihydro-1H-indole-5-sulfonamide

Participants

Reaction Steps

To a suspension of 1-acetylindoline-5-sulfonamide (Intermediate 52A, 1.00 g, 4.16 mmol) in MeOH (12.0 mL) was added conc. HCl (1.7 mL, 20.8 mmol). The resulting reaction mixture was stirred at room temperature for 18 h and then at 80° C. for 2 h. The reaction mixture was cooled to room temperature and concentrated in vacuo. The brown residue was dissolved in water and the solution was adjusted to a pH of 7-8 with 1 N aq. NaOH solution. The mixture was then extracted with EtOAc (2×), and the combined organic extracts were dried over Na2SO4, filtered and concentrated in vacuo to give the title compound (720 mg, 87%) as a light brown solid. 1H NMR (DMSO-d6) δ 7.42-7.38 (m, 2H), 6.86 (s, 2H), 6.47 (d, J=8.1 Hz, 1H), 6.24-6.22 (m, 1H), 3.53-3.50 (m, 2H), 2.98-2.95 (m, 2H); MS(ESI+) m/z 199.1 (M+H)+.

Provenance & Evidence