Reaction #674293

Reaction equation

NH4Cl

tert-Butyl 6-hydroxy-2-azaspiro[3.3]heptane-2-carboxylate

Et3N

Methanesulfonyl chloride

→

tert-butyl 6-((methylsulfonyl)oxy)-2-azaspiro[3.3]heptane-2-carboxylate

Yield 99.1%

Solvents

DCM

Conditions

Workup

1. 1
   Temperatureto warm to room temperature
2. 2
   workup.STIRRINGstirred at room temperature for 18 hrs
3. 3
   workup.STIRRINGstirred at room temperature for 10 min
4. 4
   OtherThe layers were separated
5. 5
   ExtractionThe aqueous phase was extracted with DCM (3×30 mL)
6. 6
   DryingThe combined organic phase was dried over anhydrous Na2SO4
7. 7
   Concentrationconcentrated by evaporation in vacuo

Procedure

tert-Butyl 6-hydroxy-2-azaspiro[3.3]heptane-2-carboxylate (505 mg, 2.37 mmol) was dissolved in DCM (6.0 mL). The solution was cooled to 0° C. with an external ice-bath. Et3N (330 μL, 2.37 mmol) and DMAP (3.0 mg, 0.0237 mmol) were added. Methanesulfonyl chloride (184 μL, 2.37 mmol) was then added dropwise by syringe. The solution was stirred at 0° C. for 2.0 hrs, was then allowed to warm to room temperature and stirred at room temperature for 18 hrs. A saturated solution of NH4Cl (20 mL) was added and stirred at room temperature for 10 min. The layers were separated. The aqueous phase was extracted with DCM (3×30 mL). The combined organic phase was dried over anhydrous Na2SO4, concentrated by evaporation in vacuo to afford tert-butyl 6-((methylsulfonyl)oxy)-2-azaspiro[3.3]heptane-2-carboxylate (684 mg, 99%) as a white solid.

Source