: To overcome the upsurge of antimicrobial resistance that has emerged in recent years, there is a need for the development of newer hits having gratifying anti-infective activity. Hydrazides incorporated with an azomethine hydrogen account for a cardinal class of molecules for the development of newer derivatives. Hydrazide derivatives have gainedconsiderable interest of medicinal chemists owing to their diverse bioactivity. In the present review, we have attempted to compile the recent trends in the synthesis of hydrazides and their substituted derivatives. The structural features that lead to the desired antimicrobial activity are highlighted, which will lead the way for synthetic and medicinal chemists to focus on newer designs in this arena.

Pyrimidines serve as key structural components in chemical frameworks and biological processes. Several pyrimidine analogues have been produced over the years by means of traditional methods that necessitated large amounts of solvents, reagents, and, most importantly, additional time, all of which became prohibitive. These procedures are now being replaced with more cost-effective adaptive methodologies which incorporate one-pot synthesis and greener approaches with various green solvents and catalysts. The current review covers a number of green synthetic techniques, including ultrasound-assisted synthesis, visible light irradiation synthesis, solvent-free synthesis, catalyst-free synthesis, microwave-assisted synthesis, and green catalyst synthesis for the synthesis of pyrimidine derivatives. Accordingly, it integrates different strategies to synthesize heterocyclic pyrimidine analogues in a well-organized manner.