1H-Pyrrolo(2,3-b)pyridine → 3-Chlorobenzoic Acid

Participants

Reaction Steps

The title compound was prepared according to a procedure described in WO2003082289A1. A solution of 1H-pyrrolo[2,3-b]pyridine (10.0 g, 84.6 mmol) in ethyl acetate (846 ml, 84.6 mmol) was cooled to 0° C. To the cold solution was added a solution of mCPBA (103 mmol, 23.1 g, 77% pure) in 53 mL of EtOAc over a period of 1.5 h. Halfway into the reaction, 100 mL of EtOAc was added to the reaction to ease stirring of the thick mixture. The residual mCPBA was washed into the reaction mixture by an additional portion of EtOAc (25 mL). Solid precipitated out of the solution, and the resulting mixture was warmed to rt, and allowed to stir at this temp until the starting azaindole had been consumed as judged by RPLC. After 3 h at rt, the reaction was completed. The reaction mixture was cooled back to 0° C. The resulting slurry was filtered to collect the N-oxide as the meta-chlorobenzoic acid salt. The solid was washed with additional EtOAc and dried under vacuum. The product, 1H-pyrrolo[2,3-b]pyridine 1-oxide salt of mCBA was obtained as light yellow solid.

Provenance & Evidence