Hexane ethanol diethylamine → Nedemelteon

Participants

Reaction Steps

Racemic N-[2-(2-methyl-7,8-dihydro-6H-indeno[5,4-d][1,3]oxazol-8-yl)ethyl]acetamide (768 mg, 3.00 mmol) was fractionated by high performance liquid chromatography (instrument: Prep LC 2000 (manufactured by Nihon Waters K. K.), column: CHIRALPAK AD (50 mmID×500 mL, manufactured by Daicel Chemical Industries, Ltd.), mobile phase: hexane/ethanol/diethylamine=90/10/0.1, flow rate: 60 mL/min, column temperature: 30° C., sample concentration: 1.02 mg/mL, injection weight: 31 mg). A fraction containing an optically active compound having a shorter retention time under the above-mentioned high performance liquid chromatography conditions was concentrated. The concentrate was re-dissolved in ethanol, and concentrated to dryness. Hexane was added again, and the mixture was concentrated to dryness to give the title compound (381 mg, 99.9% ee). Enantiomer excess (ee) was measured by high performance liquid chromatography (column: CHIRALPAK AD (4.6 mmID×250 mL, manufactured by Daicel Chemical Industries, Ltd.), mobile phase: hexane/ethanol/diethylamine=90/10/0.1, flow rate: 0.5 mL/min, column temperature: 30° C., sample concentration: 0.65 mg/mL (hexane/ethanol), injection volume: 10 μL).

Provenance & Evidence