Nucleophile-Mediated Ring Expansion of 5-Acyl-substituted 4-Mesyloxymethyl-1,2,3,4-tetrahydropyrimidin-2-ones in the Synthesis of 7-Membered Analogues of Biginelli Compounds and Related Heterocycles
作者:Anastasia A. Fesenko、Mikhail S. Grigoriev、Anatoly D. Shutalev
DOI:10.1021/acs.joc.7b01348
日期:2017.8.4
state and solutions were established using X-ray diffraction and NMR spectroscopy. A plausible mechanism of tetrahydropyrimidine ring expansion based on DFT calculation at B3LYP/6-31+G(d,p) level and NMR monitoring experiments was discussed. The ring contraction reaction of methoxy- or phenylthio-diazepinones under acidic conditions resulted in the corresponding 3-functionalized 1-carbamoyl-1H-pyrroles
烷基2-氧代-2,3,6,7-四氢-1 H -1,3-二氮杂-5-羧酸盐和5-酰基-2,3,6,7-四氢-1的一般六步方法基于5-官能化的4-甲磺酰氧基甲基-1,2,3,4-四氢嘧啶-2-酮的亲核试剂介导的扩环反应,已经开发了H -1,3-二氮杂-2-酮。后者的合成涉及容易获得的N -[(2-苯甲酰氧基-1-甲苯基)乙基]脲中的甲苯磺酰基被β-氧酸酯或1,3-二酮的烯醇钠亲核取代,然后将其脱水或杂环化脱水得到的产物,除去苯甲酰基保护,并将羟甲基转化为甲磺酰氧基甲基。所得四氢-1 H的构型使用X射线衍射和NMR光谱确定了固态和溶液形式的-1,3-二氮杂-2-酮。讨论了基于D3在B3LYP / 6-31 + G(d,p)水平上的DFT计算和NMR监测实验得出的四氢嘧啶环扩环的合理机理。甲氧基或苯硫基二氮杂庚酮在酸性条件下的环收缩反应产生相应的3-官能化的1-氨基甲酰基-1 H-吡咯。