Nuclear Magnetic Resonance Studies of Bicyclic Thiophene Derivatives. I. Ring Current Effects of the Benzene Ring on the H<sub>α</sub>and H<sub>β</sub>Signals of the Thiophene Ring in Benzoylthiophene, Thienopyrimidine and Thienodiazepine Derivatives
作者:Toshiyuki Hirohashi、Shigeho Inaba、Hisao Yamamoto
DOI:10.1246/bcsj.48.147
日期:1975.1
the shielding effect of the benzene ring; a steric repulsion between ortho substituent of the benzene ring and some atoms on another moiety of each molecule. Such a repulsion should bring the benzene ring out of the plane of the thiophene ring. The degree of shielding on Hβ by the benzene ring is found to increase in the order 1<2<3<4. This can be taken to indicate that the amount of steric repulsion
各种噻吩衍生物,例如 4-phenyIthienopyrimidines (1)、2-acetylamino-3-benzoylthiophenes (2)、5-phenyl-1,4-thienodiazepines (3) 和 5-phenyl-1,4-thienodiazepine-4-oxides ( 4)已经准备好了。他们的质子磁共振谱表明,随着苯环邻位取代基体积的增加,噻吩环的 Hα 和 Hβ 变得更加屏蔽。这归因于苯环的屏蔽作用;苯环的邻位取代基与每个分子另一部分上的一些原子之间的空间排斥。这种排斥应该使苯环脱离噻吩环的平面。发现苯环对Hβ的屏蔽程度按1<2<3<4的顺序增加。