Hydrogen Peroxide → 2-Carboxyphenoxathiin-10-oxide

Participants

Reaction Steps

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.

Provenance & Evidence