Carbon Dioxide → tert-butyl {[(1S,2S)-2-(2-methylpyrazolo[1,5-a]pyridin-4-yl)cyclopropyl]methyl}carbamate

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Reaction Steps

Trans-tert-butyl{[2-(2-methylpyrazolo[1,5-a]pyridin-4-yl)cyclopropyl]methyl}carbamate (4.80 g) was fractionated by supercritical fluid chromatography (instrument: Multigram II (manufactured by Mettler-Toledo), column: CHIRALPAK AD-HKG-010 (20 mm ID×250 mm L, manufactured by Dicel Chemical Industries, Ltd.), mobile phase: A) carbon dioxide 100%, B) methanol 100%, mixing ratio: A/B=900/100, flow rate: 50 mL/min, column temperature: 35° C., sample concentration: 10 mg/mL (methanol), injection volume: 2.5 mL). A fraction solution containing an optically active compound having a shorter retention time under the above-mentioned supercritical fluid chromatography conditions was concentrated to give the title compound (2.21 g, 99.9% ee). Enantiomer excess (ee) was measured using supercritical fluid chromatography (column: CHIRALPAK AD-H LA-145 (4.6 mm ID×250 mm L, manufactured by Dicel Chemical Industries, Ltd.), mobile phase: A) carbon dioxide 100%, B) methanol 100%, mixing ratio: A/B=900/100, flow rate: 2.35 mL/min, column temperature: 35° C., sample concentration: 0.5 mg/mL (methanol), injection volume: 5 μL).

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