反应详情

Phenoxathiin-2-carboxylic acid (0.61g) was dissolved in refluxing absolute ethanol (40 ml) and 30% w/v hydrogen peroxide solution (1.50 ml) added. Reflux was maintained for 2 hours, more 30% w/v hydrogen peroxide solution (1.00 ml.) added, and reflux continued for 17 hours. The solution was evaporated to low volume, and the product crystallised out. The solid was filtered, washed and dried to give 2-carboxyphenoxathiin-10-oxide m.p. 223° C. Recrystallisation from absolute ethanol raised the melting point to 237° C.

1. additionadded
2. temperatureReflux
3. temperaturewas maintained for 2 hours
4. additionadded
5. temperaturereflux
6. customThe solution was evaporated to low volume
7. customthe product crystallised out
8. filtrationThe solid was filtered
9. washwashed
10. customdried