反应详情

A mixture of 15 g of 1-(4-nitro-phenylazo)-4-(dimethylamino)naphtalene, 75 ml sodiumhydrogen sulphate nonahydrate (50% wt in water) and 80 ml of methanol was heated at reflux for 3 h. The reaction mixture was then cooled to room temperature and poured into 300 ml of water. The brownish precipitate was filtered off, washed with water (200 ml) and cold methanol-water (100 ml/100 ml) to give 12 g of nearly pure 1-(4-amino-phenylazo)-4-(dimethylamino)naphtalene as a brownish solid.

1. temperaturewas heated
2. temperatureat reflux for 3 h
3. filtrationThe brownish precipitate was filtered off
4. washwashed with water (200 ml) and cold methanol-water (100 ml/100 ml)