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

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 6-bromo-4-oxospiro[chroman-2,4′-piperidine]-1′-carboxylate (6593 g, 16.6 mol) and DMF (33 L) was added Zn(CN)2 (1947 g, 16.6 mol) and Pd(PPh3)4 (192 g, 0.17 mol). The slurry was heated to 90° C. for 3 hours, then cooled to room temperature and filtered. Water (16 L) was added to the filtrate. The resulting slurry was cooled to 5° C., stirred for 1 hour and filtered. The solid was washed with DMF/water (2:1) and dried under vacuum to give tert-butyl 6-cyano-4-oxospiro[chroman-2,4′-piperidine]-1′-carboxylate.

Provenance & Evidence