METHOD FOR PREPARING DIPHENIC ACID N-SUBSTITUTED IMIDES Russian patent published in 2006 - IPC C07D223/18 

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for synthesis of diphenic acid N-substituted imides. Method is carried out by reaction of diphenic acid with imidating agents in organic solvent medium. Process is carried out in inert organic solvent medium that forms azeotropic mixture with water at the reaction mass boiling point and involving distilling off of water formed. N,N'-disubstituted ureas of the formula: (NHR₂)CO wherein R means methyl, phenyl are used as an imidating reagent. After termination of water formation acetic anhydride is added to the reaction mass in the following mole ratio of reagents: diphenic acid : urea : acetic anhydride = 1.0:(1.0-4.0):(1.0-20.0), respectively. Method provides increasing yield of the end product and reducing toxicity and corrosive properties of reagents used.

EFFECT: improved method of synthesis.

2 tbl, 13 ex