A diversity-oriented, microwave-assisted synthesis of 4-oxo and 4-chloropyrido[2,3-d]pyrimidin-7(8H)-ones

A microwave-assisted protocol for the synthesis of 4-oxo and 4-chloropyrido[2,3-d]pyrimidin-7(8H)-ones, 13 and 9 respectively, bearing a carbon substituent at C2 and a chlorine atom at C4 is reported. The introduction of a wide range of substituents at C2 renders this methodology easily amenable to combinatorial chemistry applications. Two examples of further derivatization of compounds 9, substitution by amine and Suzuki coupling, under microwave irradiation are also described.