An Efficient Microwave‐assisted Synthesis of Pyrido[2,3‐ d ]pyrimidine Derivatives

A series of new pyrido[2,3‐ d ]pyrimidine derivatives were synthesized by multi‐component reactions of equimolar amount of aromatic aldehydes with barbituric acids (barbituric acid or 1,3‐dimethylbarbituric acid) and 5‐amino‐2‐methylbenzo[ d ]thiazol in mixed solvent of glacial acetic acid and ethylene glycol without catalyst under microwave irradiation. This one‐pot method has the advantage of good yields (90% –93%), simple workup procedure and short reaction time (5 min).