作者:T. Ashok Kumar、B. Rama Devi、P.K. Dubey
DOI:10.14233/ajchem.2013.15080
日期:——
Simple and green methodologies for the syntheses of 2-styrylbenzimidazoles (3a-c) and its N-alkyl derivatives (7a-i) have been developed. o-Phenylenediamine (1) was condensed with cinnamic acids (2a-c) resulting in 2-styrylbenzimidazoles (3a-c) using glycerol as a green and efficient solvent. 3 were also prepared alternatively by the condensation of 2-methylbenzimidazole (4) with benzaldehydes (5a-c) using glycerol as solvent. 2-Styrylbenzimidazoles (3a-c) and 2-methylbenzimidazole (4) were alkylated independently to obtain N-alkyl-2-styrylbenzimidazole (7a-i) and N-alkyl-2-methylbenzimidazole (6a-c), respectively using DMS/DES/PhCH2Cl applying green methods such as simple physical grinding of reactants in solid phase, treating reactants in PEG-600 as a solvent in solution phase and using microwave irradiation of reactants respectively. Compounds 7a-i could also be prepared, alternatively, by heating 6a-c with 5a-c in glycerol at 180 °C for 3-4 h.
开发了合成2-苯乙烯基苯并咪唑(3a-c)及其N-烷基衍生物(7a-i)的简单绿色方法。邻苯二胺(1)与肉桂酸(2a-c)在甘油作为绿色高效溶剂的条件下缩合,得到2-苯乙烯基苯并咪唑(3a-c)。另外,也可以通过2-甲基苯并咪唑(4)与苯甲醛(5a-c)在甘油溶剂中缩合制备化合物3。2-苯乙烯基苯并咪唑(3a-c)和2-甲基苯并咪唑(4)分别在DMS/DES/PhCH2Cl条件下进行烷基化,采用固相反应物简单物理研磨、PEG-600作为溶剂进行溶液相处理以及微波辐射等绿色方法,分别得到N-烷基-2-苯乙烯基苯并咪唑(7a-i)和N-烷基-2-甲基苯并咪唑(6a-c)。另外,也可以通过6a-c与5a-c在180°C甘油中加热3-4小时制备化合物7a-i。