Metal‐Free Synthesis of Coumarin‐fused Pyrimidines from 4‐Aminocoumarins via Pseudo Four‐component Reaction

Abstract An efficient pseudo four‐component procedure for the construction of chromeno[4,3‐ d ]pyrimidin‐5‐ones, a type of coumarin‐fused pyrimidines, from 4‐aminocoumarins, two molecules of aromatic aldehydes and ammonium iodide under metal‐free conditions is developed. The coumarin‐pyrimidine hybrids readily undergo sequential hydrolysis and alkylation to give all‐carbon substituted pyrimidines in excellent yields. One‐pot synthesis of pyrimidines from readily available 4‐aminocoumarins and other commodity chemicals is exemplified.