Sodium hydride → [(2S)-4-methylmorpholin-2-yl]methyl 4-phenyl-piperazine-1-carboxylate

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Reaction Steps

(S)-(4-Methyl-morpholin-2-yl)-methanol (Intermediate 10; 100 mg, 0.76 mmol) was added to a suspension of NaH (60% dispersion in oil; 90.0 mg, 2.28 mmol,) in anhydrous THF (7 mL) and stirred under nitrogen for 30 min. 4-Nitrophenyl 4-phenylpiperazine-1-carboxylate (Intermediate 2; 300 mg, 0.92 mmol) was added and the reaction mixture was stirred at room temperature for 48 h. The reaction mixture was filtered through celite and the solid washed with THF (10 mL). The filtrates were combined and the solvent removed in vacuo. The residue was purified by column chromatography (normal phase silica, 5 g Isolute-Si column, gradient 1-5% MeOH in DCM) then by reverse phase HPLC(YMC ODS-A 100×20 mm, 5 μm, 25 mL/min, gradient 20% to 100% (over 7 min) then 100% (3 min) MeOH in 10% MeOH/water). The pure product was taken up in DCM (5 mL), filtered, and dried in vacuo to give [(2S)-4-methylmorpholin-2-yl]methyl 4-phenyl-piperazine-1-carboxylate (50 mg, 20%) as a colourless gum.

Provenance & Evidence