Nuclear Magnetic Resonance Studies of Bicyclic Thiophene Derivatives. I. Ring Current Effects of the Benzene Ring on the H α and H β Signals of the Thiophene Ring …

T Hirohashi, S Inaba, H Yamamoto

Index: Hirohashi,T. et al. Bulletin of the Chemical Society of Japan, 1975 , vol. 48, # 1 p. 147 - 156

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Citation Number: 13

Abstract

Various thiophene derivatives such as 4-phenyIthienopyrimidines (1), 2-acetylamino-3- benzoylthiophenes (2), 5-phenyl-1, 4-thienodiazepines (3) and 5-phenyl-1, 4- thienodiazepine-4-oxides (4) have been prepared. Their proton magnetic resonance spectra show that H α and H β of the thiophene ring become more shielded with an increase in bulk of ortho substituent of the benzene ring. This is attributed to the shielding effect of the ...