Phthalimide potassium salt → tert-Butyl 4-(6-amino-3,5-difluoropyridin-2-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-(3,5,6-trifluoro-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester (1.59 g, 5 mmol, Example 39a), potassium phthalimide (0.93 g, 5 mmol, Aldrich) in DMF (20 mL) was heated at 140° C. with stirring for 16 h. The reaction mixture was cooled to room temperature, diluted with water (60 mL) and extracted with EtOAc (2×70 mL). The combined organic extracts were dried over Na2SO4, and filtered. The filtrate was evaporated and the residue was purified by silica gel column chromatography, eluting with 20% EtOAc in hexane to give the title compound as a yellow solid. MS (ESI, pos. ion) m/z: 315 (M+1).

Provenance & Evidence