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 being allowed to stand for heating to the room temperature, the mixture was stirred for 1. 5 hours, to which was dropwise added an aqueous HCl (1 mol/liter) solution to decompose the remaining titanium tetrachloride. Then, this was extracted with chloroform. The organic layer was washed with an aqueous NaOH (1 mol/liter) solution and a saturated saline solution, and dried over sodium sulfate, and the solvent was evaporated. The residue was suspended in ether and taken out through filtration to obtain Compound IIcc-a (8.9 g, 79%) as colorless crystals.

1. temperaturewith cooling with ice
2. stirringthe mixture was stirred for 1
3. extractionThen, this was extracted with chloroform
4. washThe organic layer was washed with an aqueous NaOH (1 mol/liter) solution
5. dry with materiala saturated saline solution, and dried over sodium sulfate
6. customthe solvent was evaporated
7. filtrationtaken out through filtration
8. customto obtain Compound IIcc-a (8.9 g, 79%) as colorless crystals