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 and a solution of 300 g of sodium hydroxide in 1 l of water was added thereto. The resulting mixture was heated under reflux on a boiling water bath for 45 min. After cooling, 3 l of water was added thereto. After extraction with 5 l of ethyl acetate, the extract was washed with dilute hydrochloric acid and then with water until the washing became almost neutral. After drying over anhydrous sodium sulfate followed by distillation of the solvent at 40° C., about 570 g of a faint yellow oil was obtained. This product was purified according to column chromatography (hexane/benzene=2:1) with about 3 kg of silica gel 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 resulting mixture was heated
5. temperatureunder reflux on a boiling water bath for 45 min
6. temperatureAfter cooling
7. extractionAfter extraction with 5 l of ethyl acetate
8. washthe extract was washed with dilute hydrochloric acid
9. dry with materialAfter drying over anhydrous sodium sulfate
10. distillationfollowed by distillation of the solvent at 40° C.