COAL CHEMISTRY .8. REACTIONS OF TETRALIN WITH COAL AND WITH SOME CARBON-14-CONTAINING MODEL COMPOUNDS

When coal was treated with tetralin-/-l4C at 400 °C, small yields of α- and π-methylnaphthalenes-l4C were observed. In order to determine the mechanism of the reaction, tetralin was heated with l4C-labeled 1, 3-diphenylpropanes (1), with 1, 3-diphenylpropene (2), and with l4C-labeled phenetoles (3). In each case methylnaphthalenes were observed, and the origins of the methyl groups were determined with carbon-14. In addition to the methylnaphthalenes, 1 and 2 also yielded toluene and ethylbenzene (after 19 h), whereas phenetole-π-14C (3-π-l4C) yielded toluene (unlabeled) plus ethyl-l4C-benzene, benzene, phenol, and a mixture of a-and /3-ethyl-l4C-naphthalenes. Crossover experiments with labeled phenetole and unlabeled ethyl p-tolyl ether proved the intramolecularity of the reaction phenetole → toluene + ethylbenzene, thus illustrating a 1, 2-phenyl shift from oxygen to carbon. © 1979, American Chemical Society. All rights reserved.