Imidazole → tert-Butyl 4-{[tert-butyl(dimethyl)silyl]oxy}-6-cyano-spiro[chroman-2,4'-piperidine]-1'-carboxylate

Participants

Reaction Steps

To a solution of 15.1 g of tert-butyl 6-cyano-4-hydroxy-spiro[chroman-2,4′-piperidine]-1′-carboxylate in DMF were added 3.6 g of imidazole and 7.95 g of TBSCl at rt, and the reaction mixture was stirred at rt for 1d. To this reaction mixture was added 598 mg of imidazole and 1.3 g of TBSCl at rt, and the reaction mixture was stirred at rt for 1d. The reaction mixture was poured into ice-cold brine, and the aqueous mixture was extracted with AcOEt twice. The combined organic layers were washed with H2O and brine, dried over Na2SO4, filtered, and concentrated in reduced pressure. The residue was purified by column chromatography on silica gel using a mixture of hexane and AcOEt (100/0-80/20) as eluent to give the intended compound.

Provenance & Evidence