Abstract Acyl iodides RCOI (R= Me, Ph) reacted with N, N-dimethylformamide and N, N- dimethylacetamide Me 2 NC (= O) R'(R'= H, Me) along two concurrent pathways involving transacylation and cleavage of the Me-N bond. The first pathway leads to the formation of acyl group exchange products, and the second, to the corresponding imides R'CON (Me) COR.