Synthesis of Organosoluble and Optically Active Poly(ester-imide)s by Direct Polycondensation with Tosyl Chloride in Pyridine and Dimethylformamide

Summary

4,4′-Oxydiphthalic anhydride (1) was reacted with L-methionine (2) in acetic acid and the resulting N,N′-(4,4′-oxydiphthaloyl)-bis-L-methionine diacid (4) was obtained in high yield. The direct polycondensation reaction of this diacid with several aromatic diols such as bisphenol A (5a), phenolphthalein (5b), 1,4-dihydroxyanthraquinone (5c), 4,4′-dihydroxydiphenyl sulfide (5d), 2,6-dihydroxytoluene (5e), 4,4′-dihydroxydiphenyl sulfone (5f) and 2,4′-dihydroxyacetophenone (5g) was carried out in a system of tosyl chloride (TsCl), pyridine (Py) and N,N-dimethylformamide (DMF). The reactions with TsCl were significantly promoted by controlling alcoholysis with diols in the presence of the catalytic amounts of DMF to give a series of optically active poly(ester-imide)s (PEI)s with good yield and moderate inherent viscosity ranging 0.21–0.71 dL/g. The polycondensation reactions were significantly affected by the amounts of DMF, molar concentration of monomers, TsCl and pyridine, aging time, addition time of diols, temperature and the reaction time. All of the above polymers were fully characterized by ¹H-NMR, FT-IR, elemental analysis and specific rotation. Some structural characterization and physical properties of these new optically active PEIs are reported.