Reactions of 1,5-disubstituted naphthalenes with phthalic anhydride
Abstract
The products from a Friedel–Crafts reaction of 1,5-dihydroxynaphthalene with phthalic anhydride have been investigated. The reaction of 1,5-dimethoxynaphthalene with phthalic anhydride and an excess of aluminium chloride gives o-(4,8-dihydroxy-1-naphthoyl)benzoic acid and the partially demethylated compound, o-(8-hydroxy-4-methoxy-1-naphthoyl)benzoic acid, while with an excess of phthalic anhydride the main products are the dimethoxy-acid and 4,8-bis-(2-carboxybenzoyl)-1,5-dimethoxynaphthalene. The structure of the latter was confirmed by conversion into dibenzo[b,k]chrysene.