反应详情

3.0 Grams (11 mmol) of 5,8-dimethyl-6-bromothiochroman-4-one and 2.2 g (22 mmol.) of O-ethylhydroxylamine hydrochloride were refluxed under heat in a mixed solvent containing 10 ml of ethanol and 10 ml of pyridine For 30 minutes. The solvents were distilled off under reduced pressure, and then the residue was treated with 5% hydrochloric acid and extracted with ethyl acetate. The so-obtained solution was consecutively washed with 5% aqueous potassium carbonate and with saturated sodium chloride solution and dried over sodium sulfate. The solvent was distilled off to give 3.2 g of 4-ethoxyimino-5,8-dimethyl-6-bromothiochroman (yield 92%).

1. temperatureunder heat in a mixed solvent
2. distillationThe solvents were distilled off under reduced pressure
3. additionthe residue was treated with 5% hydrochloric acid
4. extractionextracted with ethyl acetate
5. washThe so-obtained solution was consecutively washed with 5% aqueous potassium carbonate and with saturated sodium chloride solution
6. dry with materialdried over sodium sulfate
7. distillationThe solvent was distilled off