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.