Several potentially thermostable polyesters 3 a -I were prepared by Schotten-Baumann condensation of 2,2'-diiodo-4,4'-biphenyldicarbonyl dichloride (1) with several aromatic hydroxy compounds 2a-I. The reactivity of 1 towards various phenols was tested and the spectra of the resulting model compounds 4 a -d were compared with those of the polymers. With some exceptions (3h and 3c) the polyesters were found to be soluble in organic solvents.Their inherent viscosities vary between 0, I and 0,45 dl . g -' (in CHCI, at 25 "C). The values of the inherent viscosity were in the range of 0,06-0,45 dl/g (c = 0,2 g/dl in CHCI, at 25 "C). The melting points of the polymers were found to be higher than 300°C.