Reaction #56597

Reaction equation

1-(4-nitro-phenylazo)-4-(dimethylamino)naphtalene

sodiumhydrogen sulphate nonahydrate

methanol

→

1-(4-amino-phenylazo)-4-(dimethylamino)naphtalene

Solvents

water

Conditions

Workup

1. 1
   Temperaturewas heated
2. 2
   Temperatureat reflux for 3 h
3. 3
   FiltrationThe brownish precipitate was filtered off
4. 4
   Washwashed with water (200 ml) and cold methanol-water (100 ml/100 ml)

Procedure

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.

Source