Regioselectivity in the glycosylation of 5-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole-3-thiol
作者:El Sayed H. El Ashry、Ahmed A. Kassem、Hamida M. Abdel-Hamid、Farida Louis、Sherine A.N. Khattab、Mohamed R. Aouad
DOI:10.1016/j.carres.2009.01.026
日期:2009.4
-4H-1,2,4-triazole-3-thiol (1) and its 3-benzylsulfanyl and 3-methylsulfanyl derivatives with different glycosyl halides 2-4 has been studied in presence of base. The S-glycosides 5-7 were obtained in the presence of triethylamine, whereas the respective S,N(4)-bis(glycosyl) derivatives 8-10 were synthesized in the presence of potassium carbonate; the S,N(2)-bis(glycosyl) isomer 11 could also be isolated
5-(3-氯苯并[b]噻吩-2-基)-4H-1,2,4-三唑-3-硫醇(1)及其3-苄基硫烷基和3-甲基硫烷基衍生物的糖基卤化物的糖基化作用2 -4已在有碱的情况下进行了研究。在三乙胺存在下获得S-糖苷5-7,而在碳酸钾存在下合成相应的S,N(4)-双(糖基)衍生物8-10。在半乳糖基类似物的情况下,S,N(2)-双(糖基)异构体11也可以被分离。同样,在将1保护为3-苄基(甲基)硫烷基衍生物12或13之后,N(4)-糖基类似物14-19以及少量的S,N(2)-双(半乳糖基)异构体20和21形成了。使用AM1半经验方法进行的理论计算与实验结果吻合。