A. Fischer, C. C. Greig, Rolf Röderer
Jun 1, 1975
Citations
0
Influential Citations
4
Citations
Journal
Canadian Journal of Chemistry
Abstract
Nitration of 3,4-dimethylacetophenone in acetic anhydride gives a mixture of cis-and trans-2-acetyl-4,5-dimethyl-4-nitro-1,4-dihydrophenyl acetate as the main product, together with 3,4-dimethyl-2-, 3,4-dimethyl-5-, and 3,4-dimethyl-6-nitroacetophenone. Analogous products are obtained from 3,4-dimethylbenzophenone. Rearomatization of the adducts under mildly acidic conditions occurs via 1,4-elimination of nitrous acid to form 2-acetyl- and 2-benzoyl-4,5-dimethylphenyl acetate, respectively. In strongly acidic conditions elimination of acetic acid accompanied by 1,2- and 1,3-shifts of the nitro group occurs to form the 2- and 5-nitro derivatives of the parent ketones. The rearomatization to the nitro derivatives involves the intermediate formation of an ipso-cyclohexadienyl cation which may be trapped by anisole or mesitylene to form biphenyl derivatives.