Hydrazine → 1'-(tert-Butoxycarbonyl)-3-oxo-2,3,4,5-tetrahydrospiro[cyclopentapyrazole-6(1H),4'-piperidine]

Participants

Reaction Steps

To a solution of tert-butyl 2-(methoxycarbonyl)-1-oxo-8-azaspiro[4.5]decane-8-carboxate from Procedure 1, Step F (0.448 g, 1.46 mmol) in toluene (15 mL) was added hydrazine (0.084 mL, 1.72 mmol). The reaction mixture was refluxed for 12 h, concentrated and the residue was purified by flash chromatography eluting with 5% MeOH/dichloromethane and 0.1% triethylamine to give the title compound (0.263 g). MS/EI (acetonitrile/water): m/z 294.3 retention time=2.0 min.

Provenance & Evidence