Synthesis and evaluation of antibacterial and antifungal activities of new ( Z )-3-bromo-4-(1,3-diaryl-1 H -pyrazol-4-yl
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Med Chem Res (2013) 22:4715–4726 DOI 10.1007/s00044-013-0480-0
ORIGINAL RESEARCH
Synthesis and evaluation of antibacterial and antifungal activities of new (Z)-3-bromo-4-(1,3-diaryl-1H-pyrazol-4-yl)but-3-en-2-ones and 4-(3-methyl-1-phenyl-1H-pyrazol-5-yl)-1,3-diaryl-1Hpyrazoles Rashmi Pundeer • Sushma • Vijay Kiran • Chetan Sharma • K. R. Aneja • Om Prakash
Received: 16 August 2012 / Accepted: 9 January 2013 / Published online: 22 January 2013 Ó Springer Science+Business Media New York 2013
Abstract Bromination of 4-(1, 3-diaryl-1H-pyrazol-4-yl) but-3-en-2-ones, triggered by a combination of potassium bromide and cerium(IV) ammonium nitrate in a biphasic system consisting of water and dichloromethane furnishes the corresponding monobromo compounds 2 directly, instead of the expected dibromo compounds. The a-bromo compounds 2 were utilized as efficient precursors for the synthesis of several bipyrazolyl derivatives, 4-(3-methyl-1phenyl-1H-pyrazol-5-yl)-1, 3-diaryl-1H-pyrazoles (3). All the a-bromoenones 2 and bipyrazoles 3 are new compounds and their identity was established by m.p., spectral and analytical data. The new products 2 and 3 were tested for their in vitro antibacterial activity against Staphylococcus aureus, Bacillus subtilis (Gram positive), Escherichia coli, and Pseudomonas aeruginosa (Gram negative) and antifungal activity against Aspergilus flavus and Aspergillus niger. The antimicrobial activity of the tested compounds is compared with the commercially available antibiotic, ciprofloxacin and antifungal agent, fluconazole. Keywords Bromination Cerium(IV) ammonium nitrate Bipyrazoles Antibacterial activity Antifungal activity
R. Pundeer (&) Sushma V. Kiran Department of Chemistry, Kurukshetra University, Kurukshetra 136119, India e-mail: [email protected] C. Sharma K. R. Aneja Department of Microbiology, Kurukshetra University, Kurukshetra 136119, India O. Prakash Institute of Pharmaceutical Sciences, Kurukshetra University, Kurukshetra 136119, India
Introduction Carbon-heteroatom (C-X) bond forming reactions are of rattling importance in the domain of organic synthesis. The function of most of the organic compounds is derived from the presence of heteroatoms. For example, almost all natural products contain ether, ester or ketone C–O bonds; pharmaceuticals and conductive polymers often contain amine C–N bonds; and the heterocycles having C–N, C–O, and C–S bonds in the ring structure are found in all applications of chemistry (Hartwig, 2008). Recently, cerium(IV) ammonium nitrate [Ce(NH4)4(NO3)6] has been employed for affecting a wide range of chemical transformations (Chen et al., 2011; Kesselring et al., 2008; Nair and Deepthi, 2007; Chu et al., 2007; Dhakshinamoorthy, 2005; Nair et al., 2004; Nair et al., 2003; Nair et al., 1997a, 1997b) specifically C–C and C-X bond forming reactions (Hwu and King, 2001; Nair et al., 1997a, 1997b; Ho, 1973). Cerium(IV) ammonium nitrate is proved to be a selective, mild, and easy-to-handle mediator for the facile formation of C-X bonds
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