Acenaphthene I. The preparation of derivatives of 4,5-diamino naphthalic anhydride

Abstract

The preparation of 5-nitroacenaphthene (2) using several nitrating agents resulted in a product which was found to be contaminated with 20–30% of the 3-nitro isomeride. Separation was accomplished by t.l.c. and the n.m.r. spectra of the isomers are now reported. A new synthesis of 4,5-dinitronaphthalic anhydride (5) and an improved preparation of the dimethyl and diethyl esters of 4-nitronaphthalic anhydride and 5 is described. The esters were converted to the corresponding diamino derivatives by high pressure hydrogen–Pd reduction.