The reactivity of some carbocyclic lactams and some γ-thiolactams with ethyl chloroformate has been studied. At 25°, when reaction takes place, the corresponding lactim ether hydrochloride is formed in accord with the literature. At 110° however, the reaction yields the corresponding N-ethoxycarbonyl lactam in good yield. Investigation showed the free lactim ether to be a probable intermediate in this reaction.
