Chloroacetaldehyde → Imidazo(1,2-a)pyridine-7-carbonitrile

Participants

Reaction Conditions

Reaction Steps

Chloroacetaldehyde (˜50% in H2O, 3.24 ml, 26 mmol) was added to a stirred mixture of 2-amino-isonicotinonitrile (1.6 g, 3.4 mmol) and NaHCO3 (2.23 g, 26.5 mmol) in ethanol (20 ml) at RT under N2. The reaction was stirred and heated at 80° C. for 18 hours. After cooling to RT the volatiles were removed in vacuo and the residue was partitioned between EtOAc/H2O. This mixture was filtered to remove some dark insoluble residue. The solid was washed with MeOH. The aqueous layer was extracted with EtOAc (×2). The combined EtOAc extracts were dried (Na2SO4) and filtered. The MeOH washings were added and the volatiles were removed in vacuo. The residue was purified by chromatography on silica: 100% DCM→1% 2M NH3-MeOH/DCM to give the title product. 1H NMR (400 MHz, DMSO-d6): 8.74 (1H, dd), 8.35 (1H, s), 8.19 (1H, s), 7.86 (1H, s), 7.21 (1H, dd).

Provenance & Evidence