Water → 2-Chloro-4-hydroxybenzoic acid
Reaction equation
N[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[C:4]([Cl:11])[CH:3]=1.N([O-])=[O:13].[Na+].O>S(=O)(=O)(O)O>[Cl:11][C:4]1[CH:3]=[C:2]([OH:13])[CH:10]=[CH:9][C:5]=1[C:6]([OH:8])=[O:7]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 70 °C
Procedure
4-Amino-2-chlorobenzoic acid (10.01 g) was homogeneously dissolved in 12.5% sulfuric acid (400 ml) by heating the mixture to 70° C. and cooled with ice. An aqueous solution of sodium nitrite (4.24 g/water 12 ml) was dropwise added to this suspension over 5 min at a temperature of not more than 8° C. Five minutes later, this solution was gradually poured into water (500 ml) at 80° C., upon which vigorous bubbling occurred and the solution turned red. The reaction mixture was further stirred at 80° C. for 1 hr. After cooling, the resulting product was extracted three times with ether. The organic layers were combined, washed successively with diluted hydrochloric acid, water and saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated and a small amount of diisopropyl ether was added to allow crystallization, whereby the objective compound (6.32 g) was obtained as an orange powder.
Workup
- temperaturecooled with ice
- customvigorous bubbling
- temperatureAfter cooling
- extractionthe resulting product was extracted three times with ether
- washwashed successively with diluted hydrochloric acid, water and saturated brine
- dry with materialdried over anhydrous magnesium sulfate
- customThe solvent was evaporated
- additiona small amount of diisopropyl ether was added
- customcrystallization, whereby the objective compound (6.32 g)
- customwas obtained as an orange powder
Sources & evidence
- ORD record
- ord-a7feb71159304e24a494674fdd142f11
- Source dataset
- uspto-grants-2002_02
- Patent number
- US06348474B1
Reaction notes
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