Hydrochloric Acid → 1-Phenyl-1H-imidazo[4,5-c]pyridine-2-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

n-Butyl lithium (2.5M in hexanes, 6.8 mL, 17.1 mmol) was added to a solution of 1-phenyl-1H-imidazo[4,5-c]pyridine (1.85 g, 9.48 mmol) in THF (40 mL) at −78° C. under nitrogen. The mixture was kept at −78° C. for 15 minutes then at −10° C. for 10 minutes, and then re-cooled to −78° C. and DMF (1.5 mL, 0.190 mol) added. The reaction mixture was stirred at −78° C. for 15 minutes and −10° C. for 10 minutes. The mixture was poured into aqueous hydrochloric acid (1M, 80 mL) and the resultant mixture adjusted to pH 8 with saturated aqueous NaHCO3 (50 mL), then extracted with EtOAc (3×50 mL). The combined EtOAc extracts were dried (Na2SO4) and concentrated in vacuo. The resulting residue was in purified by chromatography (SiO2 0-10% (2M ammonia in methanol) in DCM) to give the title compound as a yellow solid (0.72 g, 34%), containing methyl hemiacetal. LCMS (method H): Rt 1.28 min, [M+H]+ 224

Provenance & Evidence