Started with anthranilic acid,
1. diazotized then decomposed via Sandmeyer reaction to get o-chlorobenzoic acid (general procedure)
2. Ullmann reaction between aniline and o-chlorobenzoic acid (Organic Syntheses, Coll. Vol. 2, p.15, 1943)
3. Intramolecular condensation of N-phenylanthranilic acid to acridone (Organic Syntheses, Coll. Vol. 2, p.15, 1943)
4. Methylation of acridone with methyl iodide to get N-methylacridone (general procedure)
5. Reductive coupling of N-methylacridone with zinc to get N,N'-dimethyl-9,9'-biacridine
6. Dissolving N,N'-dimethyl-9,9'-biacridine in hot dilute nitric acid, lucigenin crystallizing out on cooling |