PRODUCTION OF 5-PHTHALIMIDO-4-OXOPENTENOIC ACID PYRIDINE SALT

摘要

PROBLEM TO BE SOLVED: To economically and simply produce a high-purity compound useful as a raw material for various chemicals by reacting N-furfurylphthalimide with molecular oxygen in the presence of a dye sensitizer while irradiating the reactional mixture with light. SOLUTION: (A) N-Furfurylphthalimide is reacted with (B) molecular oxygen in the presence of (A) a dye sensitizer (e.g. rose bengal or erythrosine) in pyridine or a solvent containing the pyridine while irradiating the reactional mixture with light and oxidized to produce (C) 5-phthalimido-4-oxopentenoic acid pyridine salt. The solvent is removed by carrying out the distillation at 20-0 deg.C solution temperature under reduced pressure and a deposited crystal of the component (C) is washed with (D) an aprotic organic solvent (preferably a solvent containing >=50wt.% halogenated hydrocarbon organic solvent) and then separated. Furthermore, the amount of the component (A) used is 10<-4> to 1mol/l, preferably 10<-3> to 10<-4> mol/l based on 1l solvent.