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化学学报
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化学学报 ›› 2011, Vol. 69 ›› Issue (10): 1217-1224. 上一篇    下一篇

研究论文

3-乙酰基-2,3/2,5-二氢-1,5-苯并硫氮杂卓的选择性合成及其互变异构

邱召来1, 王兰芝1, 李文红2, 李媛*,1   

  1. (1河北师范大学化学与材料科学学院 石家庄 050016)
    (2河北工业职业技术学院环境与化学工程系 石家庄 050091)
  • 投稿日期:2010-08-15 修回日期:2010-12-16 发布日期:2011-01-20
  • 通讯作者: 李媛 E-mail:yuanli@mail.hebtu.edu.cn
  • 基金资助:

    国家自然科学基金项目;河北省自然科学基金

Selective Synthesis and Tautomerism of 3-Acetyl-2,3/2,5-dihydro-1,5-benzothiazepines

Qiu Zhaolai1,Wang Lanzhi1,Li Wenhong2,Li Yuan*,1   

  1. (1 College of Chemistry & Material Science, Hebei Normal University, Shijiazhuang 050016)
    (2 Environment and Chemical Engineering, Heibei College of Industry and Technology, Shijiazhuang 050091)
  • Received:2010-08-15 Revised:2010-12-16 Published:2011-01-20

PDF

990

被引次数

9

研究了温度、时间等因素对合成反应的影响, 发现亚胺型杂卓4和烯胺型杂卓5分别为速度控制产物和平衡控制产物, 并且实现了两种互变异构体的选择性合成. 用核磁共振法研究了溶剂、酸碱度对4, 5互变异构的影响, 发现两种异构体在CD3OD, DMSO-d6, C6D6以及精制的CDCl3中比较稳定, 在未精制的CDCl3中容易发生互变及开环反应, 形成3, 4, 5的平衡混合物, 并以4为主要组分. 4, 5在酸中不稳定, 但在弱碱(吡啶)中能稳定存在. 采用密度泛函理论方法在B3LYP/6-31G基组水平上对四组(八种)不同取代基的上述异构体进行了几何优化和计算. 结果表明, 烯胺型杂卓5比亚胺型杂卓4稳定, 理论计算结果与实验结果基本一致.

关键词: 1,5-苯并硫氮杂卓, 速度控制产物, 平衡控制产物, 亚胺, 烯胺, 互变异构

The selective synthesis of 2,3/2,5-dihydro-1,5-benzothiazepines was achieved by controlled reaction conditions. Detailed studies on reaction temperature, reaction time revealed that 2,3-dihydro-1,5- benzothiazepines (imine tautomers) (4) and 2,5-dihydro-1,5-benzothiazepines (enamine tautomers) (5) are speed-controlled and balance-controlled products, respectively. The imine-enamine tautomerism of 4 and 5 in different solvents was investigated by means of NMR spectroscopy. The result showed that 4 or 5 are almost stable in DMSO-d6, C6D6, CD3OD and purified CDCl3. When 4 or 5 were disolved in unpurified CDCl3, the equilibria were established between 4, 5 and 3 with the imine tautomers 4 as the major species. The interconversion of compounds 4, 5 and 3 was also observed in acidic solution of C6D6, but not in basic solution of the same solvent. The stability of 2,3/2,5-dihydro-1,5-benzothiazepine tautomers was studied by density functional theory at B3LYP/6-31G level. The theoretical results showed that enamine tautomers 5 are more stable than imine tautomers 4 which are consistent with the experimental results.

Key words: 1,5-benzothiazepine, speed-controlled product, balance-controlled product, imine, enamine, tautomerism