Triethylamine → HCID 66692713, compound

Participants

Reaction Steps

4-Amino-N-Boc-piperidine (5.00 g, 24.9 mmol) was dissolved in acetonitrile (100 mL), and phenyl chloroformate (3.46 mL, 27.4 mmol) was added dropwise thereto at 0° C., followed by stirring at room temperature for 3 hours. Water was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was washed with water and a saturated sodium chloride aqueous solution, and then dried over anhydrous magnesium sulfate. After the desiccant was filtered off, the residue obtained by evaporation under reduced pressure was dissolved in acetonitrile (50 mL), and the compound (2.88 g, 11.7 mmol) obtained in Example 34 (1) and Et3N (3.70 mL, 26.4 mmol) were added thereto, followed by stirring at 60° C. overnight. Water was added to the reaction mixture and the precipitate was collected by filtration, thereby giving tert-butyl 4-(4-(2,5-difluorobenzylidene)piperidine-1-carboxamido)piperidine-1-carboxylate (4.10 g, 38%) as a white solid. Following the procedure of Example 34 (1) and using this tert-butyl compound in place of tert-butyl 4-(2,5-difluorobenzylidene)piperidine-1-carboxylate, the title compound (quant.) was obtained as a white solid.

Provenance & Evidence