反应详情

A mixture of 11.4 g (57 mmole) of 1-(3-amino-4-chlorophenoxy)-2-propanone, 10 ml of concentrated hydrochloric acid and 150 ml of ethanol is boiled under reflux for 14 hours and subsequently concentrated by evaporation in vacuo. Ice-water is added to the residue and the whole is rendered alkaline with 3N sodium hydroxide solution and extracted with ether. The crude product obtained after drying and concentration by evaporation of the organic phase is chromatographed over silica gel with petroleum ether/methylene chloride. Recrystallisation of the pure fractions from ether/petroleum ether yields 6-amino-5-chloro-3-methylbenzofuran having a melting point of 73°-75°.

1. temperatureunder reflux for 14 hours
2. concentrationsubsequently concentrated by evaporation in vacuo
3. additionIce-water is added to the residue
4. extractionextracted with ether
5. customThe crude product obtained
6. customafter drying
7. concentrationconcentration
8. customby evaporation of the organic phase
9. customis chromatographed over silica gel with petroleum ether/methylene chloride
10. customRecrystallisation of the pure fractions from ether/petroleum ether