Synthesis of 4,4′-Bis[4-(2,5-dioxo-2,5-dihydro-1H-pyrroll-1-yl)-phenylcarbonylamino]-3,3′-dichlorodiphenylmethane and 1,4-Bis{2-[4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-phenylcarbonyloxy]ethoxy}benzene

4,4′-Bis[4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)phenylcarbonylamino]-3,3′-dichlorodiphenylme-thane has been obtained by the reaction of 4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)benzoyl chloride with 4,4′-diamino-3,3′-dichlorodiphenylmethane. 1,4-Bis[2-(4-aminophenylcarbonyloxy)ethoxy]benzene has been prepared by the reaction of potassium 4-aminobenzoate with 1,4-bis(2-chloroethoxy)benzene. The synthesized diamine has been reacted with maleic anhydride to obtain 1,4-bis[4-(2-carboxyethen-1-ylcarbamoyl)phenyl-carbonyloxyethoxyjbenzene, whose subsequent cyclization with acetic anhydride gave 1,4-bis{2-[4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-phenylcarbonyloxy]ethoxy}benzene.