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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 921949Generated: October 27, 2026

Trifluoroacetic acid → Hexahydro-2H-isothiazolo[2,3-a]pyrazine 1,1-dioxide

https://huagongshe.com/reaction/921949

Reaction equation

Participants

RoleNameHCIDCharge
ReactantTrifluoroacetic acidHCID 6422—
Reactanttert-butyl 1,1-dioxo-hexahydro-2H-1lambda6-[1,2]thiazolo[2,3-a]piperazine-5-carboxylateHCID 59215825—
SolventDichloromethaneHCID 6344—
ProductHexahydro-2H-isothiazolo[2,3-a]pyrazine 1,1-dioxideHCID 5921577583.9%

Reaction Steps

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)

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS09273057B2
Source datasetuspto-grants-2016_03
ORD IDord-8bea9b8cb3cf4972a205cf614bc493b5
Source noteuspto-grants-2016_03