Trifluoroacetic acid → Ethyl 3-amino-4-cyanopyridine-2-carboxylate

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Reaction Steps

A stirred solution of ethyl 2-cyano-2-(formyl-amino)acetate (J. Org. Chem., 1979, 44, 3835; 0.47 g, 0.003 mol), acrylonitrile (1.2 ml, 0.018 mol) and tri-fluoroacetic acid (0.02 ml, 0.0003 mol) in 1,2-dichloroethane (4 ml) was heated under reflux for 3 days. The solvent was removed by evaporation under vacuum, the residue dissolved in dichloromethane (30 ml) and the resulting solution washed with saturated aqueous sodium bicarbonate solution (30 ml). The aqueous phase was washed with dichloromethane (30 ml) and the organic solutions then combined, dried (MgSO4) and evaporated under vacuum. Chromatography of the residue on silica gel (12 g), eluting with dichloromethane:methanol (100:1), followed by crystallization from acetone:hexane, gave the title compound as a colourless solid (0.12 g, 21%), m.p. 114-116° C.

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