m-Chloroperbenzoic acid → HCID 86612973, compound

Participants

Reaction Steps

To 5-chloro-1H-pyrrolo[2,3-b]pyridine (10.0 g, 65.6 mmol) in EtOAc (70 mL) at 0° C. was added dropwise over 15 h a solution of m-chloroperbenzoic acid (57%, 17.9 g, 104 mmol) in EtOAc (80 mL). The reaction mixture was stirred for 20 h at RT. Then, the mixture was cooled to −40° C. and the solids were filtered off and rinsed with cold EtOAc. The solid was taken up in water (70 mL) and treated dropwise with 30% aq. K2CO3 until pH was 11. The solution was warmed for 30 min, cooled to 0° C., filtered and dried in vacuo. Analysis (NMR) indicated the presence of m-chloroperbenzoic acid. The solid was taken up in 10% MeOH in DCM and washed with 30% aq. K2CO3 until all m-chlorobenzoic acid was removed. The organic layer was dried over Na2SO4, filtered and concentrated to provide 2.61 g (24% yield) of 5-chloro-1H-pyrrolo[2,3-b]pyridine-N-oxide (C). The combined mother liquors were concentrated. Flash chromatography (5% MeOH-DCM) provided and additional 1.49 g (13% yield) contaminated with ˜10% of the benzoic acid. LC/MS (M+H+) 168.76.

Provenance & Evidence