Sodium hydride → 3-(2,4-dimethoxyphenyl)-3-hydroxy-5,6-dimethoxy-1,3-dihydro-2H-indol-2-one

Beteiligte Stoffe

Reaktionsschritte

293 mg of 60% sodium hydride was added under ice cooling and a nitrogen gas flow to a suspension of 1.38 g of 5,6-dimethoxy-1H-indol-2,3-dione in 30 mL of tetrahydrofuran, and the reaction mixture was stirred for 1 hour at the same temperature. A Grignard's reagent generated in 20 mL of tetrahydrofuran using 3.61 g of 2,4-dimethoxybromobenzene and 486 mg of magnesium was added dropwise over a period of 3 minutes to the reaction mixture under ice cooling, after which the reaction mixture was stirred for 13 hours at room temperature. 20 mL of saturated aqueous ammonium chloride and 40 mL of ethyl acetate were added to the reaction solution, and the reaction mixture was stirred for 30 minutes at room temperature. After liquid separation, the aqueous layer was extracted with ethyl acetate (20 mL×2), the combined organic layer was washed with saturated brine and dried with magnesium sulfate, and the drying agent was then filtered off and the filtrate was concentrated under reduced pressure. The residue thus obtained was purified by column chromatography (silica gel 60, mobile phase: ethyl acetate) to obtain 1.37 g of the titled compound (brown solid).

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