Synthesis of New Fused 3(4)-Substituted 11-Furylthieno[3,2-d]pyrimidine Derivatives

A method was developed for the synthesis of new fused 3-alkyl-substituted derivatives of thieno[3,2-d]pyrimidin-4(3H)-ones based on 11-(2-furyl)-8,8-dimethyl-7,10-dihydro-8H-pyrano[3′′,4′′:5′,6′]pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4(3H)-one via nucleophilic substitution in the pyrimidine ring. A series of fused 4-amino-substituted 11-furylthieno[3,2-d]pyrimidine derivatives was also synthesized from the corresponding 4-chloro derivative.