Synthesis of 2,2-Dimethyl-2,3-dihydropyrido[3′,2′:4,5]-thieno[3,2-d]pyrimidin-4(1H)-ones by Reaction of 3-Aminothieno[2,3-b]pyridine-2-carboxamides with Acetone

The reaction of 3-aminothieno[2,3-b]pyridin-2-carboxamides with acetone in the presence of catalytic amounts of TsOH under reflux afforded a series of new 2,2-dimethyl-2,3-dihydropyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4(1H)-ones in 88–95% yields. Possible protein targets for the new compounds were identified by molecular docking studies. 2,2-Dimethyl-3-(2-methylphenyl)-9-(4-methoxyphenyl)-7-phenyl-2,3-dihydropyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4(1H)-one exhibits antidote effect against 2,4-dichlorophenoxyacetic acid in a laboratory experiment.