Reaction #674313

Reaction equation

4-bromo-1H-pyrazole

tert-butyl 2-(methylsulfonyloxy)-6-azaspiro[3.5]nonane-6-carboxylate

Cs2CO3

→

tert-butyl 2-(4-bromo-1H-pyrazol-1-yl)-6-azaspiro[3.5]nonane-6-carboxylate

Yield 25.0%

Solvents

DMF

Conditions

Workup

1. 1
   ConcentrationIt was concentrated by rotary evaporator
2. 2
   Otherto give the residue which
3. 3
   Otherwas purified by CombiFlash (25 g silica gel column, EtOAc/Hex: 0-40%)

Procedure

To a solution of 4-bromo-1H-pyrazole (210 mg, 1.428 mmol, 1.2 equiv) and tert-butyl 2-(methylsulfonyloxy)-6-azaspiro[3.5]nonane-6-carboxylate (380 mg, 1.19 mmol, 1.0 equiv) in DMF (2.5 mL) was added Cs2CO3 (465 mg, 1.428 mmol, 1.2 equiv). The mixture was stirred at 80° C. for 3 hrs. It was concentrated by rotary evaporator to give the residue which was purified by CombiFlash (25 g silica gel column, EtOAc/Hex: 0-40%) to afford 110 mg (yield 25%) of tert-butyl 2-(4-bromo-1H-pyrazol-1-yl)-6-azaspiro[3.5]nonane-6-carboxylate (cis and trans isomers) as a colorless oil.

Source