反应详情

750 g of 5-(2-bromoethyl)-1,3-benzodioxole was dissolved in 1 l of ethanol. 312 g of thiourea was added to the solution and the mixture was heated under reflux on a boiling water bath for 2 h. The reaction mixture was cooled. A solution of 300 g of sodium hydroxide in 1 l of water was added thereto and the mixture was heated under reflux on a boiling water bath for 45 min. After cooling, 3 l of water was added thereto and the product was extracted with 5 l of ethyl acetate. The extract was washed with dilute hydrochloric acid. It was then washed with water until the washing became substantially neutral and dried over anhydrous sodium sulfate. The solvent was distilled off at 40° C. to obtain about 570 g of a faint yellow oil. It was purified according to column chromatography with about 3 kg of silica gel (hexane:benzene=2:1) to obtain 310 g of the intended compound in the form of a colorless oil.

1. temperaturethe mixture was heated
2. temperatureunder reflux on a boiling water bath for 2 h
3. temperatureThe reaction mixture was cooled
4. temperaturethe mixture was heated
5. temperatureunder reflux on a boiling water bath for 45 min
6. temperatureAfter cooling
7. extractionthe product was extracted with 5 l of ethyl acetate
8. washThe extract was washed with dilute hydrochloric acid
9. washIt was then washed with water until the washing
10. dry with materialdried over anhydrous sodium sulfate
11. distillationThe solvent was distilled off at 40° C.