反应详情

A mixture of dimethyl E,E-indole-3,6-diacrylate (1.1 g), lithium hydroxide monohydrate (1.29 g), methanol (25 ml), tetrahydrofuran (10 ml) and water (5 ml) was stirred and heated at 55°-60° for 7 hr under an atmosphere of nitrogen. The cooled mixture was diluted with water (30 ml) and acidified to pH 4 with 6M hydrochloride acid. The yellow precipitate was isolated by filtration, washed with water and dried under vacuum to give E,E-indole-3,6-diacrylic acid (0.87 g, 88%) as a solid; mp >360°; partial NMR (250 MHz, DMSO-d6): 6.33(d, J=16.0 Hz, 1H, olefinic H), 6.49(d, J=16.0 Hz, 1H, olefinic H), 11.94(br s, 1H, NH), 12.10(br s, 1H, COOH).

1. temperatureheated at 55°-60° for 7 hr under an atmosphere of nitrogen
2. customThe yellow precipitate was isolated by filtration
3. washwashed with water
4. customdried under vacuum