Chlorosulfonic acid → 2-Chlorosulfonyl-4-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]benzenepropanoic acid, methyl ester
Reaction equation
[Cl:1][S:2]([OH:5])(=O)=[O:3].[F:6][C:7]([F:27])([F:26])[C:8]([C:14]1[CH:19]=[CH:18][C:17]([CH2:20][CH2:21][C:22]([O:24][CH3:25])=[O:23])=[CH:16][CH:15]=1)([OH:13])[C:9]([F:12])([F:11])[F:10]>>[Cl:1][S:2]([C:18]1[CH:19]=[C:14]([C:8]([OH:13])([C:9]([F:12])([F:11])[F:10])[C:7]([F:6])([F:26])[F:27])[CH:15]=[CH:16][C:17]=1[CH2:20][CH2:21][C:22]([O:24][CH3:25])=[O:23])(=[O:5])=[O:3]Participants
3
Procedure
To excess chlorosulfonic acid cooled with an ice-acetone bath can be added methyl 4-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]benzenepropanoate with stirring. The solution should be stirred for several hours. Addition of the reaction mixture to ice and isolation of the product will give 2-chlorosulfonyl-4-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]benzenepropanoic acid, methyl ester. Reduction of 2-chlorosulfonyl-4-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]benzenepropanoic acid, methyl ester with zinc in acetic acid followed by isolation of the product will give 2-mercapto-4-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]benzenepropanoic acid, methyl ester.