2,6-Bis(3-hydroxyphenyl)-1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydrobenzo[1,2-c:4,5-c']dipyrrole synthesis

Yield:-

Reaction Conditions:

Stage #1: Pyromellitic dianhydride;m-Hydroxyaniline in ISOPROPYLAMIDE; for 20 h;
Stage #2: with acetic anhydride in ISOPROPYLAMIDE at 80; for 5 h;

Steps:

3 Synthesis of a Bisphenol Diimide Oligomer

EXAMPLE 3 (comparative) Synthesis of a Bisphenol Diimide Oligomer A 250 ml three-neck flask equipped with a mechanical stirrer and condenser was charged with 12.97 g (0.0586 mol) of pyromellitic dianhydride, 12.79 g (0.1172 mol) of 3-amino phenol, and 100 ml of dimethyl acetamide. The mixture was allowed to react for approximately 20 hours under nitrogen atmosphere. 22.6 ml (0.2344 mol) of acetic anhydride was then added, and the reaction temperature was increased to 80°C for a period of 5 hours. The resulting suspension was then cooled to room temperature and filtered. The product was washed with 10 ml of dimethyl acetamide and 70 ml of methanol. The product was dried in-vacuo at 75°C for 7 hours. The macromonomer was yellow, and soluble in hot DMSO and NaOH solution. It was insoluble in THF, water, methylene chloride, and ODCB.

References:

EP1140827,2006,B1 Location in patent:Page/Page column 10; 11