Trifluoroacetic acid → 1-[4-(Trifluoromethoxy)benzenesulfonyl]piperazine
Reaction equation
C(OC([N:8]1[CH2:13][CH2:12][N:11]([S:14]([C:17]2[CH:22]=[CH:21][C:20]([O:23][C:24]([F:27])([F:26])[F:25])=[CH:19][CH:18]=2)(=[O:16])=[O:15])[CH2:10][CH2:9]1)=O)(C)(C)C.C(O)(C(F)(F)F)=O>C(Cl)Cl>[F:27][C:24]([F:25])([F:26])[O:23][C:20]1[CH:21]=[CH:22][C:17]([S:14]([N:11]2[CH2:10][CH2:9][NH:8][CH2:13][CH2:12]2)(=[O:16])=[O:15])=[CH:18][CH:19]=1Participants
4
Procedure
To a cold (0 C) solution of 4-(4-trifluoromethoxy-benzenesulfonyl)-piperazine-1-carboxylic acid tert-butyl ester (1.15 g, 2.8 mmol) in DCM (3 ml) was added TFA (2 ml). The resulting solution was stirred for 1 hr. Solvent was then removed under reduced pressure. The crude solid was taken-up in AcOEt (15 ml) and washed with NaHCO3 sat (2×5 ml), water (5 ml) and finally with brine (5 ml). The organic layer was dried over MgSO4 and the solvent was removed under vacuo to yield the desired 1-(4-trifluoromethoxy-benzenesulfonyl)-piperazine as a white solid (753 mg, 87% yield).