Carbon Dioxide → Methyl 11-methoxy-6,11-dihydrodibenz[b,e]oxepin-3-carboxylate

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Reaction Conditions

Reaction Steps

3-Bromo-11-methoxy-6,11-dihydrodibenz[b,e]oxepine, 30 g, was dissolved in 500 ml of tetrahydrofuran. After cooling to -78° C., 65 ml of 1.6N n-butyl lithium/hexane solution was dropwise added to the solution in a nitrogen atmosphere followed by stirring at -78° C. for further 40 minutes. The reaction solution was dropwise added onto 100 g of dry ice, which was allowed to stand to elevate to room temperature. The solvent was distilled off under reduced pressure. To the residue obtained, were added 500 ml of methanol and 10 ml of conc. sulfuric acid. The mixture was heated to reflux for 2 hours. After allowing to cool, the solvent was distilled off under reduced pressure. The residue was extracted with 500 ml of ethyl acetate. After washing successively with saturated sodium chloride aqueous solution, saturated sodium bicarbonate aqueous solution and saturated sodium chloride aqueous solution, the extract was dried over anhydrous magnesium sulfate. The solvent was then distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (eluting solvent; hexane:ethyl acetate=1:1) to give 19.3 g of the product as pale yellow oil.

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