反应详情

Under an argon atmosphere, 1,2-dimethoxyethane (7.1 mL) was added to a solution of 4-bromo-1,2-methylenedioxybenzene (8.2 mL) in tetrahydrofuran (140 mL) under stirring at room temperature. Under stirring at −72° C., n-butyl lithium (a 1.57 mol/L hexane solution, 86.9 mL) was added dropwise to the resulting solution over 30 minutes. The resulting suspension was stirred at −50° C. or lower for 1 hour. Under stirring at −45° C., a solution of (R)-3,4-dipropyl-1,2,3-oxathiazolidine 2,2-dioxide (14.14 g) in tetrahydrofuran (34 mL) was added dropwise to the suspension over 20 minutes. The solution was stirred at 10° C. or lower for 2 hours. Water (200 mL) was added to the solution under stirring at room temperature, and the mixture was separated. To the aqueous layer was added concentrated hydrochloric acid (22.8 mL) and then diethyl ether (70 mL) under stirring at room temperature. After vigorous stirring at room temperature for 2 hours, the resulting two-layer solution was separated, and the ether layer was extracted with an aqueous 1 mol/L hydrochloric acid solution (200 mL). The aqueous layer was made basic with an aqueous 1 mol/L sodium hydroxide solution, and the organic layer and diethyl ether (100 mL) were added thereto. The organic layer was separated, washed with a saturated aqueous sodium chloride solution (30 mL), dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was purified by column chromatography (NH-DM1020, AcOEt/Hexane=1/9) to give (R)-1-(3,4-methylenedioxyphenyl)-2-propylaminopentane (8.00 g, 47% yield) as a yellow oil.

1. stirringUnder stirring at −72° C.
2. stirringThe resulting suspension was stirred at −50° C. or lower for 1 hour
3. stirringUnder stirring at −45° C.
4. stirringThe solution was stirred at 10° C. or lower for 2 hours
5. stirringunder stirring at room temperature
6. customthe mixture was separated
7. additionTo the aqueous layer was added concentrated hydrochloric acid (22.8 mL)
8. stirringdiethyl ether (70 mL) under stirring at room temperature
9. stirringAfter vigorous stirring at room temperature for 2 hours
10. customthe resulting two-layer solution was separated
11. extractionthe ether layer was extracted with an aqueous 1 mol/L hydrochloric acid solution (200 mL)
12. additionthe organic layer and diethyl ether (100 mL) were added
13. customThe organic layer was separated
14. washwashed with a saturated aqueous sodium chloride solution (30 mL)
15. dry with materialdried over anhydrous magnesium sulfate
16. concentrationconcentrated under reduced pressure
17. customThe residue was purified by column chromatography (NH-DM1020, AcOEt/Hexane=1/9)