4,4 -Biphenyldicarboxylate , aromatic

The present method for preparing aromatic dicarboxylic acids has been used to convert phthalic or isophthalic acid to tereph-thalic acid (90-95%) 2,2 -biphenyldicarboxylic acid to 4,4 -biphenyldicarboxylic acid 3,4-pyrroledicarboxylic acid to 2,5-pyr-roledicarboxylic acid and 2,3-pyridinedicarboxylic acid to 2,5-pyridinedicarboxylic acid. A closely related method for preparing aromatic dicarboxylic acids is the thermal disproportionation of the potassium salt of an aromatic monocarboxylic acid to an equimolar mixture of the corresponding aromatic hydrocarbon and the dipotassium salt of an aromatic dicarboxylic acid. The disproportionation method has been used to convert benzoic acid to terephthalic acid (90-95%) pyridine-carboxylic acids to 2,5-pyridinedicarboxylic acid (30-50%) 2-furoic acid to 2,5-furandicarboxylic acid 2-thiophenecar-boxylic acid to 2,5-thiophenedicarboxylic acid and 2-quinoline-carboxylic acid to 2,4-quinolinedicarboxylic acid. One or the other of these two methods is often the best way to make otherwise inaccessible aromatic dicarboxylic acids. The two methods were recently reviewed. ... 

Physical properties are related to ester-segment structure and concentration in thermoplastic polyether-ester elastomers prepared hy melt transesterification of poly(tetra-methylene ether) glycol with various diols and aromatic diesters. Diols used were 1,4-benzenedimethanol, 1,4-cyclo-hexanedimethanol, and the linear, aliphatic a,m-diols from ethylene glycol to 1,10-decane-diol. Esters used were terephthalate, isophthalate, 4,4 -biphenyldicarboxylate, 2,6-naphthalenedicarboxylate, and m-terphenyl-4,4"-dicarboxyl-ate. Ester-segment structure was found to affect many copolymer properties including ease of synthesis, molecular weight obtained, crystallization rate, elastic recovery, and tensile and tear strengths. 

Preparation of the starting material DIPB is typically achieved by isopropylation of benzene or cumene by use of conventional Friedel-Crafts catalysts [8] although solid acids [9], resins [10] and, more recently, zeolites [11,12] have also been mentioned as catalysts. Likewise, alkylation of polynuclear aromatics, e. g. biphenyl or naphthalene, gives rise to valuable intermediates. 4,4 -DialkyIbiphenyl can be converted into 4,4 -biphenyldicarboxylic acid, a monomer for a variety of... 

The formation of macrocycles may also concern the rigid block. Rozbs [37] prepared liquid crystalline copolymers with flexible blocks of aliphatic polyethers and rigid blocks of aromatic polyesters. They were prepared by polytransesterification of aliphatic diols with aromatic diesters derived from biphenyl or frans-stilbene. Scheme 36 shows the formation of cycles when the diester is dimethyl-2,2 -biphenyldicarboxylate. In this case, the respective location of the ester groups is responsible for the formation of the cyclic compound. 

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