Preparation
a) 1-Chloro-9,10-dioxo-9,10-dihydroanthracene-2-carboxylic acid?or 1-Nitro-9,10-dioxo-9,10-dihydroanthracene-2-carboxylic acid and 2-Aminoanthracene-9,10-dione condensation, and cyclization; (b) of Nitrobenzene in 1-Cyano-2-bromoanthraquinone?and 1-Aminoanthracene-9,10-dione condensation, and cyclization; (c)1-Chloro-9,10-dioxo-9,10-dihydroanthracene-2-carboxylic acid and 2-Benzoyl-4-methyl-5-aminobenzoic acid condensation, then with sulfuric acid cyclization. Note: some are given in the literature in the “X” a take a methyl products method of preparation.
Synthesis
1,2 : 5,6-Diphthaloylacridone, Indanthren Orange F 3R,
is prepared from 1-nitro- (or chloro-) anthraquinone-
2-carboxylic acid and 2-aminoanthraquinone
in dichlorobenzene followed by ring
closure in sulfuric acid .