反应详情

A mixture of p-nitrobenzenesulfonic acid (20 g), phosphorous pentoxide (50 g) and 1,2-dichloroethylene (100 ml) is heated at reflux for 4 days. The hot supernatant is decanted from the gummy residue and allowed to cool to room temperature. The resulting crystalline precipitate of p-nitrobenzenesulfonic anhydride (1.5 g) is collected, washed with anhydrous diethylether, and dried under vacuum. The gummy residue is twice more refluxed overnight with 100 ml portions of dichloroethylene and worked up as above to provide additional p-nitrobenzenesulfonic anhydride (4.0 g). mp 171°-172°.

1. temperatureis heated
2. temperatureat reflux for 4 days
3. customThe hot supernatant is decanted from the gummy residue
4. customThe resulting crystalline precipitate of p-nitrobenzenesulfonic anhydride (1.5 g) is collected
5. washwashed with anhydrous diethylether
6. customdried under vacuum
7. temperatureThe gummy residue is twice more refluxed overnight with 100 ml portions of dichloroethylene