triethylorthoformate Acetic anhydride → 6-Bromo-4-chloro-3-methyl-imidazo[4,5-c]pyridine

Participants

Reaction Conditions

Reaction Steps

The above crude diamine 2.59-A was dissolved in a mixture of triethylorthoformate:Acetic anhydride (1:1, 9 mL). The reaction mixture was heated to 155° C. for 1 h, cooled to rt and then evaporated. The residue was dissolved in 2.5M NaOH (20 mL) and heated at 50° C. 45 min. The resulting solution was cooled to rt, neutralized with AcOH, and cooled to 0° C. The precipitate was filtered to give 6-bromo-4-chloro-3-methyl-3H-imidazo[4,5-c]pyridine 2.60.

Provenance & Evidence