Sodium Hydroxide → 1-(4-Methoxyphenyl)-4-(2,2,4,6,7-pentamethyl-2,3-dihydro-1-benzofuran-5-yl)piperazine

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Reaction Steps

That is, to the THF (20 mL) suspension of lithium aluminum hydride (577 mg, 15.2 mmol), aluminum chloride (2.03 g, 15.2 mmol) was added under ice cooling, and then the mixture was stirred for 10 minutes and added with the THF (25 mL) solution of 5-[4-(4-methoxyphenyl)piperazin-1-yl]-2,2,4,6,7-pentamethyl-1-benzofuran-3(2H)-on (2.00 g, 5.07 mmol), and the mixture was stirred for 2 hours under reflux. After cooling the reaction solution on ice, water and 0.5 N aqueous solution of sodium hydroxide were serially added thereto. The mixture was stirred for 1 hour at room temperature, and then extraction was performed using ethyl acetate. The extract was washed with saturated saline and dried over anhydrous magnesium sulfate. After that, the solvent was removed by distillation under reduced pressure. The resulting residue was purified by silica gel chromatography (hexane-ethyl acetate 90:10-75:25) and crystallized from ethyl acetate and hexane to obtain the title compound 1.60 g as a colorless crystal (yield 83%). Melting point was 152 to 155° C.

Provenance & Evidence