反应详情

To a solution of 3,3-diethyl-1-methyl-1,3-dihydro-indol-2-one (J. Chem. Soc., 1971, 1375) (7.6 g) in concentrated sulfuric acid (12 ml) is added a mixture of nitric acid (65%, 2.7 ml) and concentrated sulfuric acid (4.4 ml) at 0° C. over a period of 30 min. The reaction mixture is stirred at this temperature for 30 min and then poured into ice water. The precipitate is collected by filtration and washed with water to give the respective compound (9.3 g).

1. filtrationThe precipitate is collected by filtration
2. washwashed with water