Aims: The study aims to synthesize thiocoumarin scaffolds clubbed with pyrimidine
and 1,3,4-oxadiazole ring system under microwave irradiation and describe their pharmacological
Background: We report herein an efficient and simple Lewis acid-catalyzed procedure for the
synthesis of novel series of thiocoumarin clubbed with pyrimidine and 1,3,4-oxadiazole motifs
under microwave irradiation. The microwave-assisted technique has many advantages, such as a
higher yield, a clean and selective procedure, shorter reaction time, and simple work-up.
Objective: The objective of the present study is to design and synthesize thiocoumarin scaffolds
clubbed with pyrimidine and 1,3,4-oxadiazole ring system by microwave-assisted heating. Our
prime focus is to highlight the synthetic approach developed for the synthesis of heterocyclic moieties
of pharmacological interest, and the prominence has also been given to distinct advantages
provided by microwave heating.
Methods: Thiocoumarin clubbed with pyrimidine, and 1,3,4-oxadiazole motifs was synthesized
under microwave irradiation. All the synthesized molecules were evicted by IR, 1H NMR, 13C
NMR, and mass spectra. The anti-microbial activity of synthesized compounds was examined
against two Gram-negative bacteria (E. coli, P. aeruginosa), two Gram-positive bacteria (S. aureus,
S. pyogenes), and three fungi (C. albicans, A. niger, A. clavatus) using the MIC (Minimal Inhibitory
Concentration) method, anti-tubercular activity H37Rv using L. J. Slope Method and anti-
oxidant activity using DPPH and ABTS bioassay method.
Results: The application of microwave technology for the rapid synthesis of biologically significant
thiocoumarin analogues is very promising because of its shorter reaction time and higher
yield. Some of these new derivatives showed moderate to good in-vitro anti-bacterial, anti-fungal,
and anti-tubercular activity. Compounds B4 and B7 appeared to have high radical scavenging efficacies
as 35.32 ± 0.446 and 33.97 ± 1.069 μg/mL ± SD of IC50 values in DPPH and ABTS bioassay,
Conclusion: Microwave-assisted synthesis provides an implicit way to discover a promising class
of molecular entities for the development of new anti-microbial and anti-oxidant agents. Oxadiazole
and pyrimidine bearing thiocoumarin derivatives showed improved anti-microbial, antitubercular,
and anti-oxidant activity.