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An efficient procedure for the synthesis of trisubstituted pyrazoles was developed. Claisen-Schmidt condensation of 2,4,5-trimethoxybenzaldehyde and substituted acetophenone in the presence of aqueous alkaline bases produced chalcones. The cyclocondensation reaction of chalcones and phenyl hydrazine hydrochloride catalyzed by an acid produced trisubstituted pyrazolines in good yields. The synthesized new compounds were characterized by spectral studies and elemental analysis and some of the intermediate chalcones by single crystal X-ray diffraction studies. The compounds were screened in vitro for their antimicrobial susceptibilities against different bacteria and fungi species.

An efficient, inexpensive and simple method for the reduction of various α,β-unsaturated ketones to corresponding saturated ketones using tosyl hydrazide as a hydrogen donor in DMF using calcium oxide powder has been reported. A variety of enones underwent reduction without forming undesirable side products. High chemoselectivity, broad functional group tolerance and good yields are the noteworthy features of this protocol.

This study demonstrates the efficient eco-friendly synthesis of a series of isoxazole derivatives 5a-h through (3+2) annulation of chalcones 3a-h and hydroxylamine (4) in citrus juice medium. The synthesized compounds were characterized by spectroscopic and CHN analysis, and assessed in vitro for their antioxidant susceptibilities by DPPH and hydroxyl radical scavenging assays. The result shows that compounds 5a, 5b, 5d and 5h have excellent DPPH and hydroxyl radical scavenging activity in both assays and therefore these molecule could serve as potent antioxidant agents.