反应详情

Ethyl 7-methoxybenzofuran-2-carboxylate (10 g) was dissolved in anhydrous methylene chloride (200 ml), to which were dropwise added dichloromethyl methyl ether (8.2 ml) and titanium tetrachloride (10 ml) with cooling with ice, and directly stirred for 30 minutes. After having been restored to be at room temperature, the mixture was stirred for further 1.5 hours. Then, an aqueous HCl (1 mol/liter) solution was dropwise added thereto to decompose the remaining titanium tetrachloride, and thereafter the mixture was extracted with chloroform. The extract was washed with an aqueous NaOH (1 mol/liter) solution and a saturated saline solution, and dried over sodium sulfate, and the solvent was thereafter evaporated. The residue was suspended in ether, and taken out therefrom through filtration to obtain Compound IIbz-s (8.9 g, 79%) as colorless crystals.

1. temperaturewith cooling with ice
2. customto be at room temperature
3. stirringthe mixture was stirred for further 1.5 hours
4. extractionthe mixture was extracted with chloroform
5. washThe extract was washed with an aqueous NaOH (1 mol/liter) solution
6. dry with materiala saturated saline solution, and dried over sodium sulfate
7. customthe solvent was thereafter evaporated
8. filtrationthrough filtration
9. customto obtain Compound IIbz-s (8.9 g, 79%) as colorless crystals