反应详情

750 g of 5-(2-bromoethyl)-1,3-benzodioxole was dissolved in 1 l of ethanol, followed by the addition of 312 g of thiourea. The mixture was heated under reflux on a boiling water bath for 2 hours and cooled, followed by the addition of a solution of 300 g of sodium hydroxide in 1 l of water. The obtained mixture was heated under reflux on a boiling water bath for 45 minutes and cooled, followed by the addition of 3 l of water. The obtained mixture was extracted with 5 l of ethyl acetate. The extract was washed with dilute hydrochloric acid and with water until the washings became neutral, dried over anhydrous sodium sulfate and distilled at 40° C. to remove the solvent. About 570 g of a yellow oil was obtained. This oil was purified by silica gel column chromatography (hexane/benzene=2:1) to obtain 310 g of the title compound as a colorless oil.

1. temperatureThe mixture was heated
2. temperatureunder reflux on a boiling water bath for 2 hours
3. temperaturecooled
4. temperatureThe obtained mixture was heated
5. temperatureunder reflux on a boiling water bath for 45 minutes
6. temperaturecooled
7. extractionThe obtained mixture was extracted with 5 l of ethyl acetate
8. washThe extract was washed with dilute hydrochloric acid and with water until the washings
9. dry with materialdried over anhydrous sodium sulfate
10. distillationdistilled at 40° C.
11. customto remove the solvent