1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → {2-Oxo-2-[4-(2-trifluoromethyl-benzoyl)-piperazin-1-yl]-ethyl}-carbamic acid tert-butyl ester

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Reaction Steps

DIPEA (3.5 mL, 20.41 mmol) was added dropwise to tert-butoxycarbonylamino-acetic acid (1.42 g, 8.16 mmol) in DMF (15 mL). EDCI (2.6 g, 13.61 mmol) and HOBT (1.1 g, 8.16 mmol) were added consecutively and, after 10 mins, piperazin-1-yl-(2-trifluoromethyl-phenyl)-methanone hydrochloride (2 g, 6.80 mmol) was added. The resulting mixture was stirred at room temperature overnight. Water was then added and the product was extracted with EtOAc and washed with brine. The organic phase was dried over Na2SO4 and concentrated under reduced pressure to afford 3.3 g of crude product. Purification by column chromatography (using silica gel of mesh size of 60-120 and 60/40 EtOAc:hexane as the eluent) afforded 2.6 g (96% yield) of {2-Oxo-2-[4-(2-trifluoromethyl-benzoyl)-piperazin-1-yl]-ethyl}-carbamic acid tert-butyl ester.

Provenance & Evidence