A green synthesis of pyrimido[4,5-b]quinolines and pyrido[2,3-d]pyrimidines via a mechanochemical approach

A cost-effective and competent approach has been established for the synthesis of pyrimido[4,5-b]quinolines and pyrido[2,3-d]pyrimidines via a multicomponent reaction of 1,3 diketones (dimedone, barbituric acid, and Meldrum's acid), 6-aminouracil and aromatic aldehyde, through mechanochemical synthesis using a ball-mill. This transformation involves a one pot, catalyst-free, and solvent-free pathway to develop the desired products under mild reaction conditions.