Аннотация:
Recyclization of 2-(R-amino)benzimidazoles with N-arylitaconimides affords new 1-R-3,4-dihydropyrimido[1,2-a]-benzimidazol-2(1H)-ones bearing acetanilide moiety at position 3. The similar reaction with α-methylene-γ-butyrolactone gives the analogues containing 2-hydroxyethyl substituent. The domino process starts with the aza-Michael addition of the 3-positioned imine atom of benzimidazoles at the activated exo-methylene group of the bielectrophiles.