Ethyl trifluoroacetate → Tert-butyl 3-(((2,3-dihydro(1,4)dioxino(2,3-c)pyridin-7-ylmethyl)(trifluoroacetyl)amino)methyl)piperidine-1-carboxylate

Participants

Reaction Steps

To a solution of 1.3 g of tert-butyl 3-(((2,3-dihydro(1,4)dioxino(2,3-c)pyridin-7-ylmethyl)amino)methyl)piperidine-1-carboxylate in 10 mL of methanol, 0.54 mL of ethyl trifluoroacetate was added, and a mixture was stirred at room temperature for 2 hours, and then stirred at 40 to 45° C. for 3 hours. Thereto was added 0.54 mL of ethyl trifluoroacetate, and the mixture was heated under reflux while stirring for 3 hours. The mixture was cooled to room temperature, and the solvent was then distilled off under reduced pressure. The resultant residue was purified by silica gel column chromatography using an eluent of hexane:ethyl acetate=1:1 to obtain 0.47 g of tert-butyl 3-(((2,3-dihydro(1,4)dioxino(2,3-c)pyridin-7-ylmethyl)(trifluoroacetyl)amino)-methyl)piperidine-1-carboxylate as a colorless oily substance.

Provenance & Evidence