Available on line www.jocpr.com Journal of Chemical and Pharmaceutical Research __________________________________________________ ISSN No: 0975-7384 CODEN(USA): JCPRC5 J. Chem. Pharm. Res., 2010, 2(4):518-525 518 Synthesis and biological studies of unsymmetrical mannopyranosyl thiocarbamides Madhukar G. Dhonde* a , Atul V. Wankhade b and Shirish P. Deshmukh c a Department of Chemistry, Shri Mathuradas Mohota College of Science, Nagpur, India b Department of Chemistry, Visvesvaraya National Institute of Techanology, Nagpur, India c Department of Chemistry, Shri Shivaji College, Akola, India ______________________________________________________________________________ ABSTRACT Synthesis of unsymmetrical N,N’-disubstituted Mannopyranosyl thiocarbamides by the interaction of N-tetra-O-acetyl-β-D-Mannopyranosyl isothiocyanate and free amines in ethanol. The polar solvent which increases the rate of reaction which was monitored by TLC while, the yield measured after completion of reaction with column chromatography. These compounds were screened for their antibacterial and antifungal activity against E. coli, S. aureus, P. vulgaris, Pseudomonas, Bacillus, S. typhi, A. niger and Fusarium.The identities of these newly synthesized compounds were established on the basis of elemental analysis UV, IR, 1 H NMR, 13 C NMR & Mass spectral studies. Keywords. Synthesis, Characterization, Mannopyranosyl isothiocyanate & thiocarbamides. ______________________________________________________________________________ INTRODUCTION Symmetric and unsymmetric thiocarbamides have been reported and tested for their biological activity. The conventional methods reported for thiocarbamides synthesis are essentially based on the reaction of amines with isothiocyanate[1-3]. In our own effort to develop and synthesized the some new N,N’-disubstituted unsymmetric thiocarbamides having Mannosyl moiety. Unsymmetric N,N’-disubstituted mixed thiocarbamides are found as main product in the reaction involving mannopyranosyl isothiocyanate 1 with free aliphatic & aromatic amines (2a-h). Here nucleophilic addition of free amines to the heterocumulated carbon atom is a main decomposition route of isothiocyanates[4] (scheme -1). In further investigation, we discovered that the yield of unsymmetric thiocarbamides significantly increased during the attempted coupling between mannopyranosyl isothiocyanate & free amines as reactive