First example of the groebke mcr using hydoxybenzal dehydes and substituted 2‐aminopyrimidines

Abstract

Abstract magnified image A three component condensation of 2‐aminopyrimidines, isocyanides and 4‐hydroxybenzaldehydes was studied. 3‐Amino‐2‐(4‐hydroxyphenyl)imidazo[1,2‐ a ]pyrimidine derivatives were obtained in moderate yields. Using 4‐hydroxy‐3,5‐dimethoxybenzaldehyde and 2‐aminopyrimidine as starting materials in the condensation led to mixtures of isomeric 2‐ and 3‐aminoimidazo[1,2‐ a ]pyrimidines. It was demonstrated, that the regiospecificity of this reaction is mainly defined by the steric hindrance of substituents on the pyrimidine nucleus and the carbonyl activity of the corresponding aldehydes.