2,4-Dichlorophenol → 3,5-Dichloro-2-hydroxybenzenesulphonyl chloride
Reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[OH:9].[Cl:10][S:11](O)(=[O:13])=[O:12].S(Cl)(Cl)=O>>[OH:9][C:3]1[C:2]([Cl:1])=[CH:7][C:6]([Cl:8])=[CH:5][C:4]=1[S:11]([Cl:10])(=[O:13])=[O:12]Participants
4
Procedure
A process comprising (1) contacting 2,4-dichlorophenol with at least 4 equivalents of chlorosulfonic acid and 0-2 equivalents of thionyl chloride, quenching the reaction product in water at 0°-60° C. to form 2-hydroxy-3,5-dichlorobenzenesulfonyl chloride, and optionally adding a chlorocarbon solvent, (2) contacting the sulfonyl chloride from (1) with at least 3 equivalents of aqueous ammonia or anhydrous ammonia at -5° to 25° C. to form 2-hydroxy-3,5-dichlorobenzenesulfonamide and (3) dehalogenating the sulfonamide by contacting the reaction product from (2) with hydrogen, in a solvent, in the presence of at least two equivalents of a base and a catalyst at a pressure of at least one atmosphere.
Workup
- customquenching the reaction product in water at 0°-60° C.
Sources & evidence
- ORD record
- ord-2c73ad5715ff48eab9877020093a6c39
- Source dataset
- uspto-grants-1985_12
- Patent number
- US04556733
Reaction notes
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