In a 2-l. round-bottomed flask equipped with a mechanical stirrer, a thermometer, and a dropping funnel, and clamped in a position such that it may be surrounded by a bath of water and ice when desired, are placed 300 g. (1.62 moles) of β-acetylaminonaphthalene (m.p. 131–132°) and 500 cc. of glacial acetic acid. With the mixture at room temperature, the stirrer is set in motion, and 200 g. (143 cc., 2.1 moles) of concentrated nitric acid (sp. gr. 1.4) is added dropwise over a period of forty-five minutes; the temperature is kept below 40° by occasionally immersing the flask in the cooling bath. When about one-tenth of the nitric acid has been added, the reaction mixture sets to a mass that is stirred with difficulty. The addition of nitric acid is stopped at this point. After three to five minutes the mass becomes fluid, and the addition of nitric acid is resumed. When about one-fourth of the nitric acid has been added, all the solid material dissolves. Considerable heat is evolved at this point, and good cooling is required to keep the temperature from rising above 40°; the mixture must be cooled during the addition of the remainder of the acid. After the addition is complete, stirring is continued for ten minutes longer.

The flask is stoppered and cooled in a bath of ice and water for three hours; the reaction product should then separate in the form of a yellow, crystalline paste (Note 1) and (Note 2). The crystals are collected on a 19-cm. Büchner funnel and washed, first with 200 cc. of 50 per cent acetic acid, and next with 400 cc. of ordinary ether. This crude, dry product, weighing 270–290 g., is placed in a 3-l. flask and heated under a reflux condenser with 1.7 l. of benzene for twenty minutes. The mixture is then allowed to cool to 40–45° and filtered through a 19-cm. Büchner funnel. The residue is a mixture of sparingly soluble isomers, chiefly 5- and 8-nitro-2-acetylaminonaphthalene. On further cooling of the filtered solution, there is obtained 190–200 g. of 1-nitro-2-acetylaminonaphthalene melting at 117–119°. This material is recrystallized from about 500 cc. of hot 95 per cent ethyl alcohol. Fine yellow crystals melting at 123–124° are obtained. The yield is 175–182 g. (47–49 per cent of the theoretical amount).