The nitration of bibenzyl. Part II. Comparison of the products from nitrations by nitric acid in acetic anhydride and by nitronium salts in organic solvents

Abstract

The nitration of bibenzyl (in excess) with a solution of nitric acid in acetic anhydride gives very little dinitration, in marked contrast to the nitration of bibenzyl (in excess) with solutions of nitronium salts in organic solvents. For the reactions with preformed nitronium ions, the isomeric composition of the dinitro-fraction and the product composition in the nitration of mixtures of bibenzyl and mononitrobibenzyls support the earlier conclusion that the dinitration arises mainly from reaction during the mixing of the reactant solutions. For dinitration, there is no evidence of a significant contribution from the addition of a nitronium ion to the first nitro-group followed by an intramolecular NO₂–transfer to the second ring.