SYNTHESIS, CHARECTERIZATION AND ANTI-MICROBIAL ACTIVITY OF SUBSTITUTED 5-(5-SULFANYL-1,3,4-OXADIAZOL-2-YL)BENZENE- 1,2,3-TRIOL DERIVATIVES

Abstract

A solution of propyl gallate(0.01 mol) in ethanol and hydrazine hydrate (0.01 mol) was refluxed for 4 hours. The excess solvent was distilled off under reduced pressure. The cooled residual mass was washed with distilled water. It was filtered and dried. The crude product was recrystallised from methanol to yield galloylhydrazide, Carbon disulfide (2 ml) was added drop wise to an ice cooled solution of KOH (2g) in ethanol (20 ml) containing the acid hydrazide 4 (0.02 mole), then the reaction mixture was stirred at room temperature 2h . After dilution with ethanol the solid precipitated was washed twice with ether. To the solid obtained (1 g), 10% KOH (20 ml) was added then the reaction mixture was refluxed for 4 hr, cooled, acidified with conc. HCl. The resulting solid was filtered washed with water, dried and crystallized. A mixture of (0.97g, 0.005mol) of 5-(5-sulfanyl- 1,3,4-oxadiazol-2-yl)benzene-1,2,3-triol and (0.005mol) of different aryl or alkyl  halides were refluxed in 25ml of pyridine solution for 3.5 hours. The resultant mixture was cooled and poured into crushed ice. The solid mass is thus separated out was dried and recrystallized from ethanol. Synthesized derivatives purity were checked by TLC, Melting point & characterized by FT-IR, Mass, NMR spectroscopic techniques. Synthesized derivatives were evaluated for anti-microbial activity.

Keywords: Oxadiazole, Oxadiazole derivatives, Anti-microbial activity.