N-(2,2-diethoxyethyl)-3-methoxy-2-nitrobenzamide → 7-methoxy-8-nitroisoquinolin-1(2H)-one

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Reaction Conditions

Reaction Steps

A mixture of N-(2,2-diethoxyethyl)-3-methoxy-2-nitrobenzamide (296a, 92 g, 0.295 mol) in concentrated sulfuric acid (1 L) was stirred at 70° C. for three hours. After cooling to room temperature, the mixture was slowly poured into ice water (3 L), causing a solid precipitate to form. The precipitate was collected by filtration. The filter cake was washed with water (1 L) and dried to yield 7-methoxy-8-nitroisoquinolin-1(2H)-one (296b, 60 g, 92% yield) as a brown solid. 1H NMR (400 MHz, DMSO-d6) δ 7.92-7.89 (d, J=9.2 Hz, 1H), 7.81-7.79 (d, J=9.2 Hz, 1H), 7.18-7.15 (t, J=6.6 Hz, 1H), 6.66-6.64 (d, J=7.2 Hz, 1H), 3.95 (s, 3H).

Provenance & Evidence