2-芳氧甲基苯并咪唑-1-乙酰肼的NMR谱的表征

摘要

利用酯3的肼解合成出了8个2-芳氧甲基苯并咪唑-1-乙酰肼(4).其中4c、4d、4f和4g是新化合物,利用元素分析、IR和1 H NMR谱对目标化合物4进行了结构表征.利用2D NMR谱(包括1H-1H COSY、HSQC、HMBC和NOESY)对代表化合物4e进行了1H和13C NMR的归属及空间结构确定.通过变温实验和溶剂实验(DMSO-d6和CDCl3)研究了化合物4e的互变异构.实验结果表明,室温下,DMSO中,目标化合物4存在着酮式和亚胺醇式这两种异构体的互变,其中酮式占88.2％～92.6％；而在CDCl3中,仅以亚胺醇形式存在.%Eight 2-aryloxymethyl-1 H-benzimidazole acetic acid hydrazides (4) have been synthesized by hydrazinolysis of the corresponding esters 3.Among them,the compounds 4c,4d,4f and 4g are new.The structures of the target compounds 4 were characterized by elemental analysis,IR and 1 H NMR.1 H and 13 C NMR signals assignments and spatial structure of representative compound 4e are confirmed by its two-dimensional (1 H-1 H COSY,HSQC,HMBC and NOESY) NMR spectra.The tautomerism of compound 4e were studied by the variabletemperature experiment and solvent experiment (DMSO-d6 and CDC13).The experimental re sults indicate that the target compounds 4 in DMSO at room temperature exist in the tautomeric keto and imine enol forms,and the dominant keto form isomer consists 88.2～92.6％,while the imine enol form is the only structure in CDC13 at room temperature.