Maleic Acid → trans-tert-butyl 5a',6',7',8',9',9a'-hexahydro-5'H-spiro[piperidine-4,4'-pyrrolo[1,2-a]quinoxaline]-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

trans-2-(1H-Pyrrol-1-yl)cyclohexanamine hydrogen chloride (989 mg, 4.93 mmol), tert-butyl 4-oxopiperidine-1-carboxylate (982 mg, 4.93 mmol), and maleic acid (56.2 mg, 0.493 mmol) were combined in ethanol (12 mL). The reaction mixture was heated at 80° C. for 4 hours. The reaction mixture was cooled to room temperature and the solvent was evaporated. The residue was dissolved in dichloromethane and was then purified on 80 g of silica gel utilizing a gradient of 0-10% methanol in dichloromethane to give trans-tert-butyl 5a′,6′,7′,8′,9′,9a′-hexahydro-5′H-spiro[piperidine-4,4′-pyrrolo[1,2-a]quinoxaline]-1-carboxylate. ESI-MS m/z calc. 345.2, found 346.2 (M+1)+; Retention time: 1.63 minutes (4 min run).

Provenance & Evidence