反应详情

温度

55 °C

Intermediate 5 was prepared according to the method described by Yang et al. (J. Am. Chem. Soc., 1996, 118, 9557), and the cyclization to the isatin was carried out as described by Marvel and Hiers (Org. Synth. Coll. Vol. I, 327). Hydroxylamine hydrochloride (11.4 g, 0.165 mol) and sodium sulfate (52 g, 0.366 mol) were placed in a 1 L round-bottomed flask, and 310 mL water, 16 mL 2 M aqueous hydrochloric acid and 2-iodoaniline (Aldrich, 10 g, 46 mmol) were added. Chloral hydrate (9.1 g, 55 mmol) was then added, and the mixture was heated at 55° C. overnight, with stirring. After cooling to room temperature, the slightly lumpy precipitate was collected by filtration, washing once with water, and dried under vacuum to yield isonitroso intermediate 5 as a beige solid (11.0 g, 83% yield): 1H NMR (400 MHz, DMSO-D6) δ ppm 6.99 (t, J=7.71 Hz, 1H) 7.41 (t, 1H) 7.63 (s, 1H) 7.76 (dd, J=8.08, 1.26 Hz, 1H) 7.90 (dd, J=7.83, 1.26 Hz, 1H) 9.38 (s, 1H) 12.42 (s, 1H).

1. temperatureAfter cooling to room temperature
2. filtrationthe slightly lumpy precipitate was collected by filtration
3. washwashing once with water
4. customdried under vacuum