Abstract: According to antibacterial characteristics of o-hydroxydiphenyl ethers and 1,2,4-triazole and the superpostion principle of reinforcement of biological activities, twelve novel 3-substituted sulfur-5-(1-hydroxyphenyl)-4H-1,2,4-triazole compounds were designd by means of combining segments o-hydroxy phenyl and 1,2,4-triazole. Firstly, salicylic hydrazide was synthesized by methylsalicylate with hydrazinehydrate in ethanol; then, salicylic hydrazide reacted with ammonium thiocyanate and HCl to obtain 5-(1-hydroxyphenyl)-4H-1,2,4-triazole-3-thiones(3); at last, under alkaline conditions, the target compounds were obtained by alkylation reaction of compound 3 with the halogenated acetophenone, chloride and iodomethane. The structures of final products were determined by 1H NMR and IR. The results of preliminary bioassay show that the title compounds have inhibitory rates about 99% against Monilia albican and Escherichia coli and a inhibitory rate about 85% against Staphylococcus aureus at 0.01% mass fraction.

Key words: 3-Substituted sulfur-5-(1-hydroxyphenyl)-4H-1,2,4-triazole, Antibacterial activity, Structure-activity relationship