Benzoic Acid → HCID 178527630, compound
Reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].O[S:10]([OH:13])(=[O:12])=[O:11].[OH:14][S:15]([OH:18])(=O)=[O:16].O=S(=O)=O.[C:23](O)(=O)[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1>O>[C:24]1([C:23]2[NH:7][C:2]3[C:3]([S:10]([OH:13])(=[O:12])=[O:11])=[CH:4][C:5]([S:15]([OH:18])(=[O:16])=[O:14])=[CH:6][C:1]=3[N:8]=2)[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 120 °C
Procedure
108 parts of o-phenylenediamine are introduced into 500 parts of H2SO4 (>96%) and then 800 parts of oleum (65%) are added dropwise, the temperature being maintained at a maximum of 120° C. After 15 min, the mixture is cooled to 70° C. and 120 parts of benzoic acid are added. The mixture is then heated for 2 h at 180° C. The mixture is then slowly hydrolysed with 2 500 parts of water, the temperature being maintained below 10° C. The precipitate (crystals) is filtered off with suction, suspended in 8 parts of water and dissolved with sodium hydroxide solution (32%) at pH =7. The solution is stirred with activated carbon until colorless, and then precipitation is induced using 96% H2SO4 at pH=1-2. 300 parts of 2-phenylbenzimidazole-4,6-disulfonic acid are obtained. The compound has an absorption maximum in the UV-B region at λmax=308 nm.
Workup
- temperaturethe mixture is cooled to 70° C.
- temperatureThe mixture is then heated for 2 h at 180° C
- filtrationThe precipitate (crystals) is filtered off with suction
- dissolutiondissolved with sodium hydroxide solution (32%) at pH =7
- customprecipitation
Sources & evidence
- ORD record
- ord-fc1afce988f24927bade98416d9f1372
- Source dataset
- uspto-grants-2003_07
- Patent number
- US06593476B2
Reaction notes
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