This book consists of three new projects: - Utility of Thiophenyl-Chalcone in Synthesis of Novel Fused Pyrimidines as Potent Antimicrobial Agents - Utility of 2-Thioxo-Pyrido[2,3-d]pyrimidinone in Synthesis of Pyrido pyrimido[2,1-b][1,3,5]thiadiazinones and Pyridopyrimido[2,1-b]thiazinones as Antimicrobial Agents - Microwave-Assisted Synthesis of Novel Azoles and Azolopyrimidines as Antimicrobial agents.