H acid → 2-Aminobenzenesulfonic acid
Reaction equation
N[C:2]1[C:11]2[C:6](=CC(S(O)(=O)=O)=CC=2O)[CH:5]=[C:4]([S:17]([OH:20])(=[O:19])=[O:18])[CH:3]=1.[N:21]1C(F)=NC(F)=NC=1F.NC1C=CC(S(O)(=O)=O)=CC=1.N([O-])=O.[Na+]>O.Cl>[NH2:21][C:5]1[CH:6]=[CH:11][CH:2]=[CH:3][C:4]=1[S:17]([OH:20])(=[O:19])=[O:18]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Procedure
12.8 g of 1-amino-8-hydroxynaphthalene-3,6-disulphonic acid in 200 ml of water are subjected to a condensation reaction with 3.8 ml of cyanuric fluoride at pH 4.0-4.5 and at 0°-5° as described in Example 3. 7.0 g of 4-aminobenzenesulphonic acid are added to the resulting solution and the pH value in the reaction mixture is kept at 5.5-6.0. The mixture is subsequently stirred at 0°-5° for one hour. A diazonium salt suspension which has been obtained from 7.0 g of 2-aminobenzenesulphonic acid in 100 ml of water and 20 ml of concentrated hydrochloric acid with 20 ml of 2N sodium nitrite solution at 0°-5° is then allowed to run in and the pH value is kept at 7.0-7.5 and the temperature at 0°-10° for the coupling. Finally, the temperature is increased to 20° in the course of 1 hour. After the coupling has ended, the dyestuff is salted out by adding 100 g of sodium chloride, filtered off and washed with 20% strength sodium chloride solution until the runnings are almost colourless. The dyestuff, which, in the form of the free acid, corresponds to the formula ##STR25## is dried at 40° in vacuo.
Sources & evidence
- ORD record
- ord-d7f6e97784d1426ba5e0b1bd5e8e28f7
- Source dataset
- uspto-grants-1984_10
- Patent number
- US04474697
Reaction notes
Loading…