Chitosan: An Efficient Promoter for the Synthesis of 2‐Aminopyrimidine‐5‐carbonitrile Derivatives in Solvent Free Conditions.

Reusable chitosan without any post-modification is found to be an efficient heterogeneous catalyst for the convenient synthesis of title compounds (IV) (12 examples) from guanidines (III), aldehydes (II), and cyanoketones such as (I).