Methyl chloroformate → Dimethyl 2-(3,5-difluoro-4-(trifluoromethyl)phenyl)-piperidine-1,4-dicarboxylate

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Reaction Steps

Methyl 2-(3,5-difluoro-4-(trifluoromethyl)phenyl)piperidine-4-carboxylate hydrochloride (3.118 g, 8.67 mmol) and DIPEA (3.02 mL, 17.34 mmol) were dissolved in DCM (30 mL). Methyl carbonochloridate (1.024 mL, 13.00 mmol) was added and the reaction stirred at room temperature for 1.5 h. Additional methyl carbonochloridate (0.341 mL, 4.33 mmol) was added and stirring continued for 0.5 h. DCM (170 mL) was added. The organic phase was washed with 0.1 M HCl (2×200 mL), satd NaHCO3 (200 mL), dried with a phase separator and evaporated in vacuo to yield dimethyl 2-(3,5-difluoro-4-(trifluoromethyl)phenyl)-piperidine-1,4-dicarboxylate (2.85 g, 86%) as a colorless oil. MS m/z 382 (M+H)+

Provenance & Evidence