反应详情

温度

-2.5 °C

A solution of 3.5 g (0.01 mol) of 4-(4-amino-3,5-dibromophenyl)-4-oxobutanoic acid in 50 ml of 1N aqueous sulphuric acid was treated dropwise with a solution of 0.76 g (0.011 mol) of sodium nitrite in 10 ml of water while maintaining a reaction temperature of −5 to 0° C. The mixture was stirred for a further 30 minutes at a temperature of 0° C., then 50 ml of hypo-phosphorous acid were added dropwise while maintaining the same temperature and stirred for another 1 hour at a temperature of 0° C. The mixture was decolorised and a colourless crystalline substance was precipitated. The mixture was diluted with 100 ml of water, the precipitate formed was suction filtered, washed thoroughly with water and then dried in a circulating air dryer. 3.1 g (92% of theoretical) of colourless crystals were obtained, m.p. 137–138° C.

1. temperaturewhile maintaining the same temperature
2. stirringstirred for another 1 hour at a temperature of 0° C
3. customa colourless crystalline substance was precipitated
4. additionThe mixture was diluted with 100 ml of water
5. customthe precipitate formed
6. filtrationfiltered
7. washwashed thoroughly with water
8. customdried in a circulating air dryer
9. custom3.1 g (92% of theoretical) of colourless crystals were obtained