Thionyl Chloride → 2-bromo-1H,4H,5H,6H,7H,8H-pyrrolo[3,2-c]azepin-4-one

Participants

Reaction Conditions

Reaction Steps

Thionyl chloride (0.06 mL, 0.90 mmol) was added to a solution of 2-bromo-6,7-dihydro-1H-indol-4(5H)-one oxime (305a) (186 mg, 0.81 mmol) in THF (8.0 mL) at 25° C., and the resulting solution was stirred at 25° C. for 18 h. The reaction mixture was then diluted with EtOAc (40 mL), sequentially washed with saturated aq. NaHCO3 (2×30 mL) and brine (20 mL), dried over Na2SO4, filtered, and concentrated in vacuo. Chromatographic purification of the residue (silica gel, 0-10% MeOH/DCM) furnished 2-bromo-5,6,7,8-tetrahydropyrrolo[3,2-c]azepin-4(1H)-one (102 mg, 0.44 mmol, 55% yield) as a light-brown solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 11.59 (1H, br. s.), 7.36 (1H, t, J=4.5 Hz), 6.27 (1H, d, J=2.7 Hz), 3.09-3.16 (2H, m), 2.82 (2H, t, J=6.6 Hz), 1.82-1.91 (2H, m). m/z (ESI, +ve) 228.9/231.1 (M+H)+.

Provenance & Evidence