反应详情

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)

1. customSolvent was evaporated
2. dissolutionthe residue was redissolved in DCM
3. concentrationconcentrated again
4. customThe crude was purified by SCX cartridge
5. washwashed with additional MeOH
6. customProduct was recovered
7. washeluting with 2M NH3 in MeOH
8. customSolvent evaporation