Hydrochloric Acid → (S)-3-[(R)-1-(3-methoxyphenyl)ethylamino]pyrrolidine dihydrochloride

Beteiligte Stoffe

Reaktionsschritte

To a solution of 8.0 g of (R)-1-benzyl-3-pyrrolidinol and 16.5 ml of diisopropylethylamine dissolved in 400 ml of methylene chloride was added dropwise a solution of 13.4 g of anhydrous trifluoromethanesulfonic acid in 50 ml of a methylene chloride at −20° C. or lower. The reaction mixture was stirred for 15 minutes while maintaining it to −20° C., then, a solution of 9.88 g of (R)-1-(3-methoxyphenyl)ethylamine in 100 ml of methylene chloride was added dropwise to the mixture at −20° C. or lower, and the reaction mixture was stirred at room temperature for 16 hours. To the reaction mixture were added a saturated aqueous sodium bicarbonate solution and chloroform, the mixture was stirred and the liquids were separated. The organic layer was dried and concentrated, and the residue was purified by silica gel column chromatography (chloroform:methanol=1:0→50:1) and NH silica gel column chromatography (hexane:ethyl acetate=25:1→10:1) to obtain 3.98 g of (S)-(1-benzylpyrrolidin-3-yl)-[(R)-1-(3-methoxyphenyl)ethyl]amine. MS•APCI (m/z): 311 [M+H]+ (2) To a solution of 3.67 g of (S)-(1-benzylpyrrolidin-3-yl)-[(R)-1-(3-methoxyphenyl)ethyl]amine dissolved in 100 ml of methanol were added 830 mg of palladium hydroxide and 8.85 ml of a solution of 4M hydrochloric acid in dioxane, and the mixture was shaked under hydrogen atmosphere at 3 atm at room temperature for 3 days. Palladium hydroxide was removed, and the solvent was evaporated. To the residue was added methanol, and the resulting precipitates were collected by filtration, washed with methanol and dried to obtain 1.14 g of (S)-3-[(R)-1-(3-methoxyphenyl)-ethylamino]pyrrolidine dihydrochloride (the following Reference example Table, Reference example 1.001).

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