Microwave-assisted polycondensation of 4,4 '-(hexafluoroisopropylidene)-N,N '-bis(phthaloyl-L-leucine) diacid chloride with aromatic diols

A new facile and rapid polycondensation reaction of 4,4'-(hexafluoroisoprop ylidene)-N,N'-bis(phthaloyl-L-leucine) diacid chloride (1) with several aro matic diols such as phenol phthalein (2a), bis phenol-A (2b), 4,4'-hydroqui none (2c), 1,4-dihydroxyanthraquinone (2d), 1,8-dihydroxyanthraquinone (2e) , 1,5-dihydroxy naphthalene (2f), dihydroxy biphenyl (2g), and 2,4-dihydrox yacetophenone (2h) was performed by using a domestic microwave oven in the presence of a small amount of a polar organic medium such as o-cresol. The polymerization reactions proceeded rapidly, compared with the conventional solution polycondensation, and was completed within 10 min, producing a ser ies of optically active poly(ester-imide)s with quantitative yield and high inherent viscosity of 0.50-1.12 dL/g. All of the above polymers were fully characterized by IR, elemental analyses, and specific rotation. Some struc tural characterization and physical properties of this optically active pol y(ester-imide)s are reported. (C) 2000 John Wiley & Sons, Inc.