Department of Chemistry, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031, South Africa.
Molecules. 2013 Nov 19;18(11):14293-305. doi: 10.3390/molecules181114293.
In an attempt to synthesize a 2-substituted benzimidazole from the reaction of o-phenylenediamine and isophthalic acid in the presence of acetone and ethanol under microwave irradiation, a salt of the isophthalate ion and 2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepin-5-ium ion was obtained. The condensation of two moles of acetone with the amine groups resulted in the formation of the benzodiazepine which crystallized as an iminium cation forming a salt with the isophthalate anion. The formation of benzodiazepine was also confirmed by performing the reaction of o-phenylenediamine with excess acetone in ethanol under conventional heating conditions. The compounds were characterized by NMR, FTIR, HRMS and microanalysis as well as X-ray crystallography. The reaction mechanism leading to the formation of benzodiazepine is also discussed.
在微波辐射下，尝试使用邻苯二胺和异酞酸在丙酮和乙醇的存在下合成 2-取代苯并咪唑，得到了异酞酸盐离子和 2,2,4-三甲基-2,3-二氢-1H-1,5-苯并二氮杂卓-5-翁离子的盐。两摩尔的丙酮与胺基缩合形成了苯并二氮杂卓，它结晶为亚胺阳离子，与异酞酸盐阴离子形成盐。通过在常规加热条件下使邻苯二胺与过量的丙酮在乙醇中反应，也证实了苯并二氮杂卓的形成。通过 NMR、FTIR、高分辨率质谱和微量分析以及 X 射线晶体学对化合物进行了表征。还讨论了形成苯并二氮杂卓的反应机理。
