The Pseudo‐Michael Reaction of 1‐Aryl‐4,5‐dihydro‐1H‐imidazol‐2‐amines with Ethyl Ethoxymethylenecyanoacetate.

The products (III) of the title reaction, on heating in acetic acid, undergo cyclization to 2,3-imidazo[1,2a]pyrimidines (IV) only, whereas on melting, a mixture of compounds (IV) and (VI) is obtained due to transesterification during the chromatographic separation of the compounds (VI).