Abstract Nitration occurs ipso to the ethyl group for p-ethyltoluene, p-diethylbenzene and ethylmesitylene. No evidence was found for ipso-nitration for 2,4,6-trimethyl-, 4-methoxy-, 4-bromo- and 2,2',4,4',6,6'- hexamethoxy-biphenyls. ... Introduction Electrophilic attack at a methyl- or methylene-substituted position on a benzene ring is now a well established process in solutions of nitric acid in acetic anhydride.IF4 Early studies showed that such ipso ...
