Water → benzyl(R)-3-[(R)-1-(naphthalen-1-yl)ethylamino]piperidine-1-carboxylate

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Reaction Steps

To a solution containing 54.6 g of benzyl (R)-3-[chlorocarbonyl-(R)-1-(naphthalen-1-yl)ethylamino]piperidine-1-carboxylate dissolved in 700 ml of tetrahydrofuran was added 350 ml of water, and the mixture was stirred under reflux for 15 hours. After tetrahydrofuran was evaporated, a saturated aqueous sodium bicarbonate solution and chloroform were added thereto, 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 (hexane:ethyl acetate=4:1→0:1) to obtain 24.3 g of benzyl (R)-3-[(R)-1-(naphthalen-1-yl)ethylamino]piperidine-1-carboxylate. MS•APCI (m/z): 389 [M+H]+ (6) To a solution containing 24.2 g of benzyl (R)-3-[(R)-1-(naphthalen-1-yl)ethylamino]piperidine-1-carboxylate dissolved in 250 ml of methanol was added 2.5 g of palladium carbon (10% wet), and the mixture was shaked under hydrogen atmosphere at 3 atm at room temperature for 40 hours. Palladium carbon was removed, and the solvent was evaporated, the residue was washed with ethyl acetate-chloroform (10:1), and collected by filtration to obtain 15.3 g of (R)-3-[(R)-1-(naphthalen-1-yl)ethylamino]piperidine (the following Reference example Table, Reference example 3.001(a)). MS•APCI (m/z): 255 [M+H]+ (7) By using 14.5 g of benzyl (S)-3-[chlorocarbonyl-(R)-1-(naphthalen-1-yl)ethylamino]piperidine-1-carboxylate, the same treatment was carried out as in the above-mentioned (5) to obtain 4.74 g of benzyl (S)-3-[(R)-1-(naphthalen-1-yl)ethylamino]piperidine-1-carboxylate. MS•APCI (m/z): 389 [M+H]+

Provenance & Evidence