反应详情

3.52 ml of titanium tetrachloride are added dropwise to a mixture of 4.0 g of ethyl 4,5-dichloro-1,3-benzodioxole-2-carboxylate, 2.12 ml of dichloromethoxymethane and 60 ml of methylene chloride at -60° C. and the mixture is stirred at room temperature for 2 days. 2.1 ml of dichloromethoxymethane and 2.1 ml of titanium tetrachloride are added to the reaction mixture at -60° C. and the mixture is stirred at room temperature for 18 hours. The reaction mixture is poured into a mixture of ethyl acetate and an aqueous sodium bicarbonate solution, and the organic layer is separated. The organic layer is washed with water, dried and evaporated to remove solvent. The residue is purified by silica gel column chromatography to give 3.21 g of ethyl 4,5-dichloro-6-formyl-1,3-benzodioxole-2-carboxylate.

1. stirringthe mixture is stirred at room temperature for 18 hours
2. customan aqueous sodium bicarbonate solution, and the organic layer is separated
3. washThe organic layer is washed with water
4. customdried
5. customevaporated
6. customto remove solvent
7. customThe residue is purified by silica gel column chromatography