A synthesis of the unknown azacyclopropenone (azirinone) system was attempted via α-azido ketenes. Treatment of α-azido acid chlorides with triethylamine, in an attempt to generate α-azido ketenes, led in good yield to nitriles containing one less carbon. At -60° it was possible to trap the α-azido ketene 7c with benzalaniline to form a β-lactam. The formation of nitriles most likely proceeds by intermediacy of an azirinone. The sequence of reactions provides a useful degradation of carboxylic acids to nitriles with loss of one carbon.