SYNTHESIS OF SOME NEW 1, 3-DI METHYL SUBSTITUTED GUANIDINE WITH POSSIBLE ANTIBACTERIAL AND ANTIFUNGAL ACTIVITY

The compounds containing thiazole, thiadiazole, oxazole, oxadiazole, imidazole, pyrimidine, pyridine & benzothiazole rings have been found to exhibit broad spectrum of biological activities.Derivatives of 1, 2, 4-thiadiazole and 1, 2, 4-thiadiazolidines exhibit antibacterial and antifungal activity1. Thiazolyl guanidines2 and various substituted aryl guanidine’s have been found to exhibit antibacterial & antifungal activities3.Keeping all these views in mind attempts were made to synthesized some new 1,3-di methyl Substituted Guanidine.In the present work 2,4 Dimethyl -3,5-(di Aryl imino)-1,2,4-thiadiazolidines were prepared by nitrous acid oxidation of N-methyl –N Aryl thiourea4 & 2,4 dimethyl-3,5-(diaryl imino)-1,2,4-thiazolidines were converted to corresponding 1,3 di methyl substituted guanidine’s by their acid catalyzed re-arrangment5.(Scheme-1)Antibacterial & Antifungal activity of the title compounds were evaluated against two bacteria, E.coli & lactobacillus & two fungi, A.Brassicicola & Aspergillus Niger. N=methyl-N`-Aryl thiourea (1-10) were prepared by refluxing a mixture of different 2-Amino Heterocyclic moieties with methyl iso thiocyanate in Ethanol.A mixture of compound (1-100 and conc. HCl, ethanol was added drop wise & under stirring to a solution of NaNO2 in water afforded 2, 4-dimethyl-3,5-(di Aryl imino)-1,2,4-thiadiazolidine (11-20) afforded 1,3 di methyl substituted guanidine’s (21-30). Structures of the compounds were established by elemental analysis & spectral data.