Synthesis and kinase inhibitory potencies of new pyrido[3,4-g]quinazolines substituted at the 8-position

As part of the structure-activity relationship study undertaken around the pyrido[3,4-g]quinazoline moiety, new derivatives substituted at the 8-position were synthesized and evaluated regarding their ability to inhibit various protein kinases (CDK5, CLK1, DYRK1A, CK1, GSK3). Most active compound exhibited a nanomolar potency toward CLK1, demonstrating that substitution at 8-position is compatible with CLK1 inhibition.