反应详情

A mixture of 3,4-pyridine-dicarboxylic acid (15 g) and acetic anhydride (30 ml) is refluxed for 2 hours. The acetic anhydride in excess is distilled off and the residue is purified by sublimation (123° C. at 3 mmHg) to give 10.1 g of 3,4-pyridine-dicarboxylic acid anhydride, a white solid, m.p. 74-76° C.

1. temperatureis refluxed for 2 hours
2. distillationThe acetic anhydride in excess is distilled off
3. customthe residue is purified by sublimation (123° C. at 3 mmHg)