Hydrochloric Acid → 4-Imidazo[1,2-a]pyridin-7-ylbenzaldehyde

Participants

Reaction Conditions

Reaction Steps

A mixture of bromoacetaldehyde diethyl acetal (0.49 mL, 23.3 mmol, 2.0 equiv) and concentrated HCl (0.05 mL, 0.4 equiv) in water (10 mL) was stirred at 23° C. for 2 h, then heated at 80° C. for 30 min. The mixture was allowed to cool to 23° C., and 4-(2-aminopyridin-4-yl)benzaldehyde (2-2, 323 mg, 1.63 mmol, 1 equiv) and NaHCO3 (324 mg, 3.91 mmol, 2.40 equiv) were added. The resulting mixture was then heated to 50° C. where MeOH (2 mL) and dioxane (3 mL) were added to increase solubility. The reaction mixture was stirred at 50° C. for 18 h, then concentrated. The residue was partitioned between EtOAc (200 mL) and brine (200 mL). The organic layer was concentrated to provide 4-imidazo[1,2-a]pyridin-7-ylbenzaldehyde (2-3) as a brown solid. LRMS m/z (M+H) Calcd: 223.2, found 223.0.

Provenance & Evidence