Synthesis And Antibacterial Activity Of Benzimidazole And Benzothiazole Sulfone Derivatives

In this work, we designs and synthesizes a series of core-benzimidazole and core-benzothiazole compounds containing sulfone structures according to the connecting principle of active subunit groups, and changes substituent group at the 5-position of benzimidazole ring, synthesized 22 target compounds. The structures were confirmed by 1H NMR, 13 C NMR and IR spectra. The results were summarized as follows:1. we use 2-amino benzimidazole and 2-amino benzothiazole as reactants to synthesis N-(benzimidazlyl-2) ethyl carbamate and N-(benzothiazlyl-2) ethyl carbamate, and through the reaction of sulfochlorination, reduction and etherification, the reaction conditions of compounds was optimized, involved with investigation of reaction solvents, reaction time, reaction temperature, acid-accepter. Take compound F1 as a modele, the optimized reaction condition was using CH3 CN as solvent, K2CO3 as catalyst, 60°C as reaction temperature, refluxing for 8 h.2. All compounds were evaluated antifungal activity against six fungi: Cytospora mandshurica, Thanatephorus cucumeris, Botrytis cinerea, Botrytis cinere, Verticillium daliae, Phytophthora infestans, and Gibberella zeae by the growth rate method incomparison with abendazole. The result of bioassay demonstrated that most of the compounds had certain antifungal activity. At the reagent concentration of 50 ?g/m L, compounds B1, D1 and E16 showed inhibition against Riziocotinia solani at 80%, 44% and 41% respectively, paralleled to Abendazole(61%); compounds B1 and D1 showed inhibition against Phytophthora infestans at 83% and 54% respectively, which were parallel to Abendazole(61%); compounds E16 showed inhibition against Verticillium daliae at 69%, which Abendazole was 38%.