反应详情

A 45.0 g amount of (62.5%) 1-naphthylamine-3,7-disulfonic acid is suspended in 200 ml of water and 30 ml of 5 N sodium hydroxide is added to it. The solution is warmed and absolute ethyl alcohol is added until a cloudy precipitate forms. The solution is cooled and the solid is collected by filtration and is washed with 85% ethyl alcohol, ethyl alcohol and ether. The product is dried in vacuo at 110° C. to give 21.0 g of 4-amino-2,6-naphthalenedisulfonic acid disodium salt.

1. temperatureThe solution is warmed
2. temperatureThe solution is cooled
3. filtrationthe solid is collected by filtration
4. washis washed with 85% ethyl alcohol, ethyl alcohol and ether
5. customThe product is dried in vacuo at 110° C.