4-Methylmorpholine → methyl (5R)-1-{(2S)-2-((tert-butoxycarbonyl)amino)-2-cyclopentylethanoyl}-5-((trimethylsilyl)ethynyl)-L-prolinate

Beteiligte Stoffe

Reaktionsschritte

To a stirred solution of methyl (5R)-5-((trimethylsilyl)ethynyl)-L-prolinate (1.2 g, 5.32 mmol) in dichloromethane (30 mL) at ambient temperature under nitrogen was added 4-dimethylamino pyridine (0.65 g, 5.32 mmol), 4-methylmorpholine (0.9 mL, 7.98 mmol), 1-(3-(dimethylamino)propyl)-3-ethyl carbodiimide hydrochloride (1.22 g, 6.39 mmol), and (2S)-((tert-butoxycarbonyl)amino)(cyclopentyl)acetic acid dicyclohexylamine salt (1.55 g, 6.39 mmol). The reaction mixture was stirred at room temperature for 16 hours, diluted with ethyl acetate and washed with 1 M HCl. The aqueous layer was further extracted with ethyl acetate (2×) and the combined ethyl acetate layers were dried (Na2SO4) and evaporated. The residue was purified by flash chromatography 30% ethyl acetate/hexane to provide the titled compound. MS (CI) m/e 451 (M+H)+.

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