A. Arcoria, E. Maccarone, G. Musumarra
Aug 1, 1972
Citations
0
Influential Citations
10
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Nitration of 2-benzylthiophene with nitric acid (molar ratio 1:1) in acetic anhydride gave only nitro-2-benzylthiophenes, indicating the benzene ring is unreactive to this electrophilic substitution. The main reaction product was 2-benzyl-5-nitrothiophene (about 87%) the amounts of the 3-nitro and 4-nitro isomers were about 10% and 3%, respectively. These percentages, determined by glc and nmr techniques, were found to be constant using various nitration conditions. The syntheses of the nitro-2-benzylthiophenes are described, together with some spectroscopic properties. The uv spectra confirm that the conjugation of the nitro group in the α position is greater than in the β position. The isomer structures have been assigned by nmr chemical shifts and coupling constant of the thiophene protons. Also infrared spectra are briefly considered.