Dimethylformamide → Tert-butyl 6-cyano-4-oxo-3,4-dihydrospiro[1-benzopyran-2,4'-piperidine]-1'-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of tert-butyl 6-bromo-4-oxospiro[chroman-2,4′-piperidine]-1′-carboxylate (143 g, 0.36 mol), Zn(CN)2 (84.7 g, 0.72 mol), Pd(PPh3)4 (20 g, 17 mmol) and dry DMF (1 liter) was stirred under an argon atmosphere at 90° C. for 6 hours. The resulting mixture was, after cooled, diluted with ethyl acetate (1 liter), and washed with aqueous 12% ammonia, water, and saturated brine in order. The organic layer was dried over sodium sulfate, and concentrated, and the residue was treated with methanol, and the resulting insoluble solid was taken out through filtration, and dried under a reduced pressure to obtain tert-butyl 6-cyano-4-oxospiro[chroman-2,4′-piperidine]-1′-carboxylate as a colorless solid.

Provenance & Evidence