| abstract |
1. IN A PROCESS FOR THE PREPARATION OF BIS-MALEIMIDES, WHICH COMPRISES EFFECTING REACTION BETWEEN A BIS-MALEAMIC ACID WHICH HAS THE GENERAL FORMULA HOOC-CH=CH-CO-NH-D-NH-CO-CH=CH-COOH IN WHICH D HAS ONE OF THE FOLLOWING MEANINGS: A LINEAR OR BRANCHED ALKYLENE RADICAL OF 2-12 CARBON ATOMS; PHENYLENE; CYCLOHEXYLENE; NAPHTHYLENE; A PLURALITY OF PHENYLENE OR CYCLOHEXYLENE RADICALS LINKED BY A SIMPLE VALENCY BOND OR BY AN ATOM OR GROUP WHICH IS INERT UNDER THE REACTION CONDITIONS; AND A LOWER CARBOXYLIC ACID ANHYDRIDE IN THE PRESENCE OF A TERTIARY AMINE AND AN ORGANIC DILUENT WHICH IS LIQUID UNDER THE REACTION CONDITIONS, THE IMPROVEMENT WHEREIN THE REACTION IS CARRIED OUT IN THE PRESENCE OF A CATALYTIC AMOUNT OF A CATALYST CONSISTING OF A NICKEL SALT OR DIVALENT NICKEL COMPLEX WHICH IS SOLUBLE IN THE LIQUID PHASE OF THE REACTION MIXTURE, FROM 0.2 TO 1 MOLE OF TERTIARY AMINE BEING USED PER MOLE OF BIS-MALEAMIC ACID. |