A new macrocyclic arylene ether sulfone bearing two carboxylic groups, 4, was prepared by use of pseudo high dilution techniques. In a first step, 4,4-bis[4-(4-(4-chlorophenylsulfonyl)phenoxy)phenyl]pentanoic acid (3) was prepared from bis(4-chlorophenyl) sulfone (1) and an excess of 4,4-bis(4-hydroxyphenyl)pentanoic acid (2). Then, the purified trimer 3 was cyclocondensed with 4,4-bis(4-hydroxyphenyl)pentanoic acid (2), yielding the bifunctionalized macrocycle 4. The existence of the ring-shaped molecule was proved by use of MALDI-TOF, NMR-and IR-spectroscopy. The free carboxylic groups of 4 were used to build up polyamides that contain the macrocycle in the main chain and 4,4'-diaminodiphenylmethane (5) as an aromatic diamine.