Synthesis of New 2-Substituted Fused Thienopyrimidin-4-ones by Bubbling Hydrogen Chloride Gas through an Alcoholic Solution of [b]-Fused 2-Amido-3-cyanothiophenes and Their Antibacterial Activity

The acylation of some 2-aminocycloalka[ b ]thiophene-3-carbonitriles with various acid chlorides gave the corresponding N -acylamino derivatives which were cyclized to fused thieno[2,3- d ]pyrimidin-4-ones by bubbling hydrogen chloride gas through their solutions in ethanol. Most of the synthesized compounds showed weak antibacterial activity against S. aureus , and some of them exhibited moderate activity against B. subtilis .