Trifluoroacetic acid → (R)-1-(2-fluorophenylsulfonyl)piperidin-3-amine

Participants

Reaction Steps

(R)-3-Boc-aminopiperidine (1.05 g, 5.25 mmol) was dissolved in DCM (10 mL) and then triethylamine (1.10 mL, 7.89 mmol) was added. To this solution at room temperature was added 2-fluorobenzenesulfonylchloride (1.127 g, 5.79 mmol). After 2 h, reaction was deemed complete by LCMS and diluted with water and extracted with DCM (30 mL), and the organic layer was separated and dried over magnesium sulfate, filtered and concentrated and taken to the next step as such. The crude product from above was dissolved in DCM (25 mL) and TFA (10 mL) added in one portion. Reaction mixture followed by LCMS. After 1 h, TFA was stripped in vacuo and then the residue suspended in 3N HCl and washed with ether. The aq. layer was basified and extracted with DCM and the DCM layer separated and dried over magnesium sulfate, filtered and concentrated in vacuo to give 873 mg of (R)-1-((2-fluorophenyl)sulfonyl)piperidin-3-amine as the desired product as free base. LCMS (m/z): 255.5 (MH+), 0.49 min.

Provenance & Evidence