反应详情

Isopropyl 3-(1,3-benzodioxol-5-yl)-3-oxopropionate (2.5 g) was dissolved in 30 ml of DMSO, to which 2.2 ml of 10N potassium hydroxide and 0.7 ml of carbon disulfide were added under ice cooling. The temperature of the resulting mixture was allowed to rise to room temperature, at which the mixture was stirred for 1 hour. The reaction mixture then turned to a reddish clear solution. After the reaction mixture was ice-cooled again, 1.066 g of cis-1,2-dichloroethylene were added, the temperature of the resultant mixture was allowed to rise to room temperature, followed by stirring for 3 hours. When the solution was poured into ice water, crystals precipitated. Those crude crystals were recrystallized from benzene-hexane, whereby 385 mg of isopropyl 2-(1,3-dithiol-2-ylidene)-3-[3,4-(methylenedioxy)phenyl]-3-oxopropionate were obtained as reddish crystals (yield: 11%).

1. additionwere added under ice cooling
2. customto rise to room temperature, at which
3. temperaturecooled again
4. customto rise to room temperature
5. stirringby stirring for 3 hours
6. customprecipitated
7. customThose crude crystals were recrystallized from benzene-hexane