Process for the preparation of aromatic orthodinitriles

Claim 1

IN THE MANUFACTURE OF AROMATIC ORTHODINITRILES FROM THE ANHYDRIDES OF AROMATIC ORTHODICARBOXYLIC ACIDS WHEREIN ALL REACTIONS ARE EFFECTED IN THE PRESENCE OF AN INERT, WATER-IMMISCIBLE, LIQUID ORGANIC SOLVENT HAVING A BOILING POINT BETWEEN 100* AND 250*C., THE NEW AND IMPROVED METHOD WHICH COMPRISES FORMING A MIXTURE OF THE ANYHYDRIDE, UREA AND SAID WATER-IMMISCIBLE ORGANIC SOLVENT AND HEATING THE MIXTURE UNDER REFLUX UNTIL THE ANHYDRIDE IS CONVERTED INTO THE CORRESPONDING AROMATIC ORTHODICARBOXYLIC IMIDE AND A DISPERSION OF SAID IMIDE COMPOUND IN SAID SOLVENT IS OBTAINED, REACTING THE IMIDE COMPOUND, IN SITU, IN SAID WATER-IMMISCIBLE SOLVENT WITH 2 TO 4 EQUIVALENTS OF CONCENTRATED AQUEOUS AMMONIA TO CONVERT THE SAID IMIDE INTO THE CORRESPONDING AROMATIC ORTHOCARBOXYLIC DIAMIDE, IN SITU, AND REMOVING THE WATER BY AZEOTROPIC DISTILLATION TO PRODUCE A DISPERSION OF THE SAID DIAMIDE IN SAID WATER-IMMISCIBLE SOLVENT, AND REACTING THE DIAMIDE, IN SITU, IN SAID ORGANIC SOLVENT WITH AT LEAST 2 MOLS OF PHOSPHOROUS OXYCHLORIDE AND AT LEAST 4 MOLS OF A TERTIARY NITROGEN BASE AT AN ELEVATED TEMPERATURE TO PRODUCE THE CORRESPONDING AROMATIC ORTHODINITRILE, IN SITU, AND RECOVERING THE SAID ORTHO DINITRILE FROM THE REACTION MIXTURE.