Reaction of enaminonitriles with isocyanates. Synthesis of new 2-oxo- and 6-oxopyrimidines

The reaction of enaminonitriles 1 with aryl or benzyl isocyanates afforded C- 3–5 or N-adducts 6–8 or a mixture of both depending on the substitution pattern of the considered enaminonitrile. The one-step synthesis of 6-oxopyrimidines 9–11 and 2-oxopyrimidines 12–14 by cyclization of compounds 3–5 and 6–8 respectively is also described.