Synthesis, Charectertisation and Antitubercular Evaluation of Pyarzoline Clubbed Thiazole Hybrids

Abstract

In our previous work, we have synthesised novel isoxazole conjugated pyrazoline derivatives by reacting isoxazolyl chalcones (1-15) with thiosemicarbazide in glacial acetic acid. From these compounds, 15 isoxazole conjugated pyrazoline carbothioamides were synthesised, compounds 24 and 25 are selected for further optimisation. In continuation to this work, pyrazoline-clubbed thiazole hybrids were synthesied by using potential antimycobacterial isoxazole conjugated pyrazoline carbothioamides – 24 and 25. The pyrazoline-1-carbothioamides- 24 (3-(isoxazol-5-yl)-5-(3,5-dimethoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide) and 25 (3-(isoxazol-5-yl)-5-(2,3,4-trimethoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide) were further optimized and synthesized eight more compounds (24a-24d, 25a-25d) which have a substituted thiazole ring. These compounds are purified by recrystallisation and charecterised by FT IR, 1 H NMR and Mass spectra. Compound 24a have shown potent antimycobacterial activity.