Microwave-assisted solvent free efficient synthesis of 1,3,4-oxadiazole-2(3H)-thiones and their potent in vitro urease inhibition activity

A review on the development of urease inhibitors as antimicrobial agents against pathogenic bacteria

“…The oxadiazole core was also explored by Shahzada and coworkers, who evaluated different substituted phenyl rings and aliphatic chains at position 5 of the oxadiazole rings ( Scheme 32 ) [86] . The activity of halogenated rings decreases from ortho to para patterns, the exception being a bromo-substituted ring, where the para -bromo displays the highest activity of all synthesized compounds.…”

Recent advances in thymidine phosphorylase inhibitors: syntheses and prospective medicinal applications

“…31 The Mannich bases 45a and 45b were synthesized by reaction of compounds 44a and 44b with formalin and primary amines in 43%…”

“…The 5-substituted 1,3,4-oxadiazoline-2-thiones 44a and 44b precursors were synthesized by the reaction of acid hydrazides 43a and 43b with carbon disulfide in KOH under microwave irradiation. 31 The Mannich bases 45a and 45b were synthesized by reaction of compounds 44a and 44b with formalin and primary amines in 43% and 94% yields, respectively (Scheme 11). 32 Scheme 11.…”

Microwave-Assisted Synthesis of Five-MemberedO,N,N-Heterocycles

“…Conversion of aromatic hydrazides into 1,3,4-oxadiazoles is more convenient and afforded 89-98% yield but in the case of aliphatic hydrazide conversion is poor and relatively less yield is obtained. [56] CONCLUSION Microwave-assisted green synthesis is a very good technique in the field of green chemistry and by governs a flexible platform for heterocycle ring formation. This feature article has highlighted the tremendous impact of the application of MW irradiation on the development of new and efficient synthetic approaches for the generation of oxygen-and nitrogen-containing five-membered heterocycles over the past decade.…”