ORIGINAL RESEARCH Synthesis and evaluation of 4-amino-5-phenyl-4H- [1,2,4]-triazole-3-thiol derivatives as antimicrobial agents Prasanta K. Sahoo Æ Rajesh Sharma Æ Priyabrata Pattanayak Received: 27 December 2008 / Accepted: 10 February 2009 / Published online: 17 March 2009 Ó Birkha ¨user Boston 2009 Abstract A series of novel 1,2,4-triazole derivatives have been synthesized by condensing the methyl benzoate and methyl salicylate with various substituents; their structures were established on the basis of elemental analysis, Fourier trans- form infrared spectroscopy (FTIR), 1 H nuclear magnetic resonance (NMR), and mass spectral data. All title compounds were subjected to in vitro antibacterial and antifungal screening against four different bacterial and fungal strains. Preliminary results indicate that some of them exhibit promising activities and deserve further consideration as potential antimicrobials. Keywords 1,2,4-Traizole Á Antibacterial screening Á Antifungal screening Introduction The usage of most antimicrobial agents is limited, not only by the rapidly developing drug resistance, but also by the unsatisfactory status of present treatments of bacterial and fungal infections and drug side-effects (Fidler, 1998). Therefore, the development of new and different antimicrobial drugs is a very important objective and many research programs are directed towards the design of new antimicrobial agents. During the last few decades, considerable attention has been devoted to synthesis of 1,2,4-triazole derivatives possessing such comprehensive bioactivities as antibacterial, antifungal (Karabasanagouda et al., 2007; Sztanke et al., 2008), P. K. Sahoo Á R. Sharma School of Pharmacy, Devi Ahilya Vishwavidyalaya, Takshashila Campus, Khandwa Road, Indore 452017, Madhya Pradesh, India P. Pattanayak (&) Jeypore College of Pharmacy, Jeypore(K), Orissa 764002, India e-mail: priyabrata2005@gmail.com Med Chem Res (2010) 19:127–135 DOI 10.1007/s00044-009-9178-8 MEDICINAL CHEMISTR Y RESEARCH