Hydrochloric Acid → HCID 86694695, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-ethyl-5-nitro-1H-benzo[d]imidazole-1-carboxylate (13.6 g, 0.052 mol) in dry DCM (140 mL) was added TFA (20 mL, 0.26 mol, 5.0 equiv.), and the reaction mixture was heated at 40° C. for 16 h. The reaction mixture was concentrated and the crude solid re-dissolved in an acetone and water mixture (1:1, 40 mL). Concentrated HCl (14 mL) and sodium nitrite (3.95 g, 0.057 mol, 1.1 eq.) were then added at 0° C., and the reaction mixture was stirred at the same temperature for 30 min. The resulting solution was added dropwise to a solution of sodium cyanide (10.21 g, 0.21 mol, 4 equiv.) and CuCN (10.5 g, 0.084 mol, 1.6 equiv.) in an EtOAc and water mixture (1:1, 40 ml) at 0° C. The reaction mixture was then warmed to RT and stirred for a further 2 h. The reaction mixture was quenched with water and extracted with EtOAc. The combined organic layers were washed with brine then dried (Na2SO4), filtered and concentrated. The crude product was purified by SiO2 chromatography eluting with 25% EtOAc/hexane to afford 4-ethyl-1H-benzo[d]imidazole-5-carbonitrile (6.8 g, 76% yield) as a yellow solid.

Provenance & Evidence