Acetic Anhydride → HCID 71112459, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-((2-amino-2,2-diphenylacetyloxy)-methyl)piperidine-1-carboxylate (prepared as in Preparation intermediate 12 with diphenylglycine replacing cyclohexylmandelic acid) (0.50 g, 1.18 mmol) in DCM (1.5 mL) was added a solution of acetic anhydride (0.122 mL, 1.30 mmol) in DCM (0.5 mL). The reaction mixture was heated at 40° C. for 18 hours. The reaction mixture was allowed to cool to RT and further acetic anhydride (0.06 mL, 0.65 mmol) added. The reaction mixture was heated at 40° C. for a further 18 hours. The reaction mixture was allowed to cool to RT, quenched with water, and the mixture was stirred at RT for 1 hour. The reaction mixture was then partitioned between saturated aqueous sodium hydrogen carbonate and DCM. The organic phase was removed and the aqueous phase extracted with further DCM. The combined DCM extracts were washed with brine, dried (magnesium sulfate), filtered, and concentrated under reduced pressure. The product was isolated (0.541 g, >100%). The crude product was used without further purification in the next step.

Provenance & Evidence