Synthesis and alkylation of 5-(3-chlorobenzo[<i>b</i>]thien-2-yl)-4<i>H</i>-1,2,4-triazole-3-thiol under classical and microwave conditions. AM1 semiemperical calculations for investigating the regioselectivity of alkylation
作者:E. S. H. El Ashry、A. A. Kassem、H. Abdel-Hamid、F. F. Louis、S. H. A. N. Khattab、M. R. Aouad
DOI:10.1002/jhet.5570430602
日期:2006.11
Under microwave irradiation (MWI), 5-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole-3-thiol (3) was synthesized in a good yield by intramolecular cyclization of the carbonyl thiosemicarbazide 2. A regioselective S-alkylation of 3 with benzyl chloride or allyl bromide has been achieved by using triethylamine as a base, while other different basic conditions led to a mixture of bis(alkylated) derivatives
在微波辐射(MWI)下,通过分子内环化反应合成了较高产率的5-(3-氯苯并[ b ]噻-2-基)-4 H -1,2,4-三唑-3-硫醇(3)。羰基氨基硫脲2.阿区域选择性的S-烷基化3与苄基氯或烯丙基溴已经通过使用三乙胺作为碱来实现,而其它不同的基本条件导致双(烷基化)衍生物n的混合物4,S-和S ,N 2-在古典和MWI条件下都可以。通过AM1方法计算反应物的相对稳定性,电荷密度,偶极矩和电子能量,过渡态和中间体,并将其用于研究区域选择性。