Naphthalene tetrachlorides and related compounds. Part 6. Alkaline dehydrochlorination of some 1-arylnaphthalene tetrachlorides
Abstract
By heterolytic chlorination of 1-(p-nitrophenyl)-, 1-(p-chlorophenyl)-, 1-phenyl-, and 1-(p-methylphenyl)-naphthalene, the corresponding 1-aryl-r-1,c-2,t-3,t-4-tetrachlorotetralins have been prepared. Alkaline dehydrochlorination of each of these tetrachlorides gives the corresponding 1-aryl-2,3-dichloronaphthalene, with its 1-aryl-2,4-dichloro-isomer as an accompanying minor component. The observed rate coefficients have been dissected to derive rates for the two competing processes of bimolecular elimination, both of which are modestly favoured by electron withdrawal in the aryl group. The implications of these findings in relation to the mechanisms and transition states for these eliminations are discussed.