Solid-phase synthesis of pyrido[2,3-d]pyrimidin-7-ones

A novel solid-phase method for the synthesis of 4-methyl-pyrido[2,3-d]pyrimidin-7-one compounds with two diversity points is described. The polymer supported methylsulfonyl derivatives A3, achieved by coupling compound G with different resin-bound amines A1 followed by oxidation with MCPBA, are substituted with several amines R1R2NH. Final cleavage affords 126 compounds having formula H in good yield and purity.