Gewald reaction for the synthesis of benzo[4,5]-thieno[2,3-d]pyrimidin-4(3H)-one derivatives and it’s antimicrobial study

A variety of schiff base of 3-amino-2,7-dimethyl-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one have been synthesized using novel and yield efficient protocol i.e., Gewald condensation reaction by four step processes. The characterization of synthesized diverse molecules was characterized by various spectroscopic methods such as IR, Mass, and NMR. The hybrids of thieno-pyrimidines were utilized to check their efficiency as anti-microbial activity against various Gram-positive (S. aureus, S. pyogenes, MRSA- multi-resistance S. aureus) and Gram negative (E. coli, P. aeruginosa, Klebsiella pneumonia) bacteria, using five anti-microbial agents as reference standard. It was found that 4a (anti-fungal agent) and 4e (anti-bacterial agent) shown best efficiency and which can lead in the area of medicinal field.