Diethyl Ether → 4-[(s)-1-(2-Chloropyridin-4-yl)ethyl]-6,6-dimethylmorpholine-2,3-dione

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Reaction Conditions

Reaction Steps

Lithium perchlorate (10.2 g) was added to a solution of (S)-1-(2-chloropyridin-4-yl)ethylamine obtained in Example 51 (1 g) in an ether (18.5 mL), and the reaction solution was stirred for five minutes. Isobutylene oxide (1.7 mL) was added to the reaction solution, which was then stirred overnight. A 5 N sodium hydroxide solution was added to the reaction solution at 0° C., followed by extraction with chloroform. The organic layer was dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. Dichloromethane (20 mL) and pyridine (20 mL) were added to the residue, and the reaction solution was cooled to 0° C. Oxalyl chloride (669 μL) was added to the reaction solution, which was then stirred at 0° C. for one hour and at room temperature for one hour. Oxalyl chloride (0.4 mL) was added to the reaction solution, which was further stirred for one hour. The solvent was evaporated under reduced pressure. Water and ethyl acetate were added to the residue, and the organic layer was separated. The organic layer was dried over magnesium sulfate, and the residue was purified by silica gel column chromatography (Chromatorex; elution solvent: heptane-ethyl acetate) to obtain the title compound (1.07 g). The property values of the compound are as follows.

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