Trifluoroacetic acid → Hexahydro-2H-isothiazolo[2,3-a]pyrazine 1,1-dioxide
Reaction equation
[S:1]1(=[O:18])(=[O:17])[N:5]2[CH2:6][CH2:7][N:8](C(OC(C)(C)C)=O)[CH2:9][CH:4]2[CH2:3][CH2:2]1.C(O)(C(F)(F)F)=O>C(Cl)Cl>[S:1]1(=[O:17])(=[O:18])[N:5]2[CH2:6][CH2:7][NH:8][CH2:9][CH:4]2[CH2:3][CH2:2]1Participants
4
Procedure
tert-butyl tetrahydro-2H-isothiazolo[2,3-a]pyrazine-5(3H)-carboxylate 1,1-dioxide (200 mg, 0.724 mmol) in DCM (3 mL) was treated with TFA (1.059 mL, 13.75 mmol) at room temperature for 1 h. Solvent was evaporated and the residue was redissolved in DCM and concentrated again. The crude was purified by SCX cartridge, loading with MeOH, washed with additional MeOH. Product was recovered eluting with 2M NH3 in MeOH. Solvent evaporation give hexahydro-2H-isothiazolo[2,3-a]pyrazine 1,1-dioxide (107 mg)