Triethylamine → tert-Butyl 2-[(3R*,4S*)-1-[(2,6-dichlorophenyl)methyl]-3-[(1-hexylpiperidin-4-yl)carbamoyl]-4-methylpyrrolidin-3-yl]acetate

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Reaction Steps

1-Hexylpiperidin-4-amine obtained in Example 10a (894 mg, 4.85 mmol), triethylamine (1.04 ml, 7.46 mmol), N,N-dimethylformamide (10 ml) and PyBOP (2.52 g, 4.85 mmol) were added to (3RS,4SR)-3-[2-(tert-butoxy)-2-oxoethyl]-1-[(2,6-dichlorophenyl)methyl]-4-methylpyrrolidine-3-carboxylic acid obtained in Example 10g (1.5 g, 3.73 mmol), followed by stirring at room temperature overnight. Water was added to the reaction mixture, which was extracted with ethyl acetate. The organic layer was washed with water and brine and dried over sodium sulfate. This was concentrated, and the crude product was purified by column chromatography (NH silica gel, elution solvent: ethyl acetate/heptane) to give a white solid (1.85 g). This was optically resolved by HPLC (CHIRALPAK IA (3 cm diameter×25 cm), elution solvent: ethanol/hexane=6/94, flow rate: 20 ml/min.) to give a chiral form corresponding to the peak with a shorter retention time (875 mg).

Provenance & Evidence