反应详情

Anisil (6.5 g), made by the oxidation of anisoin with copper sulphate in pyridine, was added to acetic acid (50 g) and heated to reflux to form a solution. Hydrobromic acid (s.g. 1.48) was added at reflux until anisil just started to precipitate (about 30 ml HBr being needed). After 2 hours' reflux, more hydrobromic acid (50 ml) was added, and the solution was refluxed for a further 2 hours. After this time, thin layer chromatography showed complete conversion into a single product. The solution was poured into cold water (600 ml) to precipitate a white solid. This was filtered off, washed with water and dried to give 5.5 g of 4,4'-dihydroxybenzil. This was used without further purification.

1. temperatureheated
2. temperatureto reflux
3. customto form a solution
4. customto precipitate (about 30 ml HBr being needed)
5. temperatureAfter 2 hours' reflux
6. additionmore hydrobromic acid (50 ml) was added
7. temperaturethe solution was refluxed for a further 2 hours
8. additionThe solution was poured into cold water (600 ml)
9. customto precipitate a white solid
10. filtrationThis was filtered off
11. washwashed with water
12. customdried