2-芳氧甲基苯并咪唑-1-乙酰肼的NMR谱的表征(英文)

NMR Spectroscopic Characterization of 2-Aryloxymethyl-1H-benzimidazole Acetic Acid Hydrazides

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1H NMR谱对目标化合物4进行了结构表征.利用2DNMR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-lH-benzimidazole acetic acid hydrazides （4） have been synthe- sized 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 1H NMR. 1H and 13C NMR signals assignments and spatial structure of representative compound 4e are confirmed by its two-dimensional （1 H_IH COSY, HSQC, HMBC and NOESY） NMR spectra. The tautomerism of compound 4e were studied by the variable- temperature experiment and solvent experiment （DMSO-d6 and CDC13）. The experimental results 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 CDCla at room temperature.