Ammonia → (2S)-N,N-dibenzyl-2-methoxy-3-(4-methylpiperazin-1-yl)propan-1-amine

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Reaction Steps

Tert-butyl 4-[(2S)-3-(dibenzylamino)-2-methoxy-propyl]piperazine-1-carboxylate 35b (4.36 g, 9.60 mmol) was dissolved in 30 mL of dichloromethane followed by the addition of 20 mL of a 4 M solution of hydrogen chloride in dioxane. The reaction solution was stirred for 0.5 hours. The resulting solution was concentrated under reduced pressure. The residue was added with 30 mL of acetonitrile, 30 mL of water and formaldehyde (0.58 g, 19.20 mmol) successively. The reaction solution was stirred for 0.5 hours, added with sodium triacetoxyborohydride (6.10 g, 28.80 mmol). The reaction solution was stirred for 1 hour. The resulting solution was added dropwise with aqueous ammonia to adjust pH to 9 to 10 and extracted with ethyl acetate (50 mL×3). The combined organic phase was washed with saturated sodium chloride solution (20 mL), then dried over anhydrous magnesium sulfate, filtered and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography to obtain the title compound (2S)—N,N-dibenzyl-2-methoxy-3-(4-methylpiperazin-1-yl)propan-1-amine 38a (2.90 g, yield: 83.0%) as a brown oil.

Provenance & Evidence