Methyl iodide → tert-butyl 4-[(2S)-3-(dibenzylamino)-2-methoxy-propyl]piperazine-1-carboxylate

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Reaction Steps

Sodium hydride (333 mg, 8.30 mmol) was dissolved in 50 mL of tetrahydrofuran, added dropwise with a solution of tert-butyl 4-[(2S)-3-(dibenzylamino)-2-hydroxy-propyl]piperazine-1-carboxylate 35a (3.65 g, 8.30 mmol) in tetrahydrofuran in an ice-water bath. The reaction solution was stirred for 10 minutes and warmed up to room temperature. The reaction solution was stirred for 1 hour and cooled down to 0° C. followed by the addition of methyl iodide (1.18 g, 8.30 mmol). The reaction solution was stirred for 12 hours. The resulting solution was added with 10 mL of saturated sodium bicarbonate solution and extracted with ethyl acetate (50 mL×3). The combined organic phase was washed with saturated sodium chloride solution (50 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 tert-butyl 4-[(2S)-3-(dibenzylamino)-2-methoxy-propyl]piperazine-1-carboxylate 35b (2.10 g, yield: 56.0%) as a yellow oil.

Provenance & Evidence