Sulfuric Acid → 7-Methyl-5-azaphenanthrene-1,10-dicarboxylic Anhydride

Beteiligte Stoffe

Reaktionsschritte

A mixture of 4-amino-1,8-naphthalic anhydride (Okazaki, M.; Ishikawa, N. Yuki Gosei Kagaku Kyokai Shi 1956, 14, 398; Chem. Abstr. 1957, 51, 8051c) (28.0 g, 131 mmol), ferrous sulfate heptahydrate (7.20 g, 25.8 mmol), concentrated sulfuric acid (13 mL, 234 mmol), and nitrobenzene (27.0 mL, 262 mmol) in acetic acid (260 mL) was heated to reflux. Methallylidene diacetate (43.5 mL, 262 mmol) was added dropwise over a period of 2.5 h using an addition funnel. After the addition was complete, the reaction mixture was heated for 1.5 h and poured into a beaker of ice/water (500 mL). The aqueous solution was further diluted to 800 mL with water, stirred for 1 h and filtered by suction. The residue was washed with water and dried in vacuo to obtain 32.3 g of a dark brown solid. The crude solid was heated at reflux in acetic acid (80 mL) and filtered hot to obtain 15.63 g (44%) of a light brown solid: mp >290° C.; MS m/e 264 (M+H+); 1H NMR (DMSO-d6, 300 MHz) δ 2.60 (s, 3H), 8.10 (t, 1H), 8.60 (s, 1H), 8.62 (s, 1H), 9.01 (s, 1H), 9.12 (d, 1H), 9.45 (d, 1H).

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