1-1’-biphenyl-2,2’,6,6’-tetracarboxylic

Generally, synthesis of dianhydrides is somewhat more complex than that of diamines and until recent time pyromellitic dianhydride (PMDA) and benzophenone-3,3, 4,4 -tetracarboxylic dianhydride (BTDA) had been the only commercially produced aromatic dianhydrides. Some of the significant commercial products developed recently, are Upilex by UBE Ind. and Ultem by General Electric. The former is based on biphenyl-3,3, 4,4 -tetracarboxylic dianhydride (BPDA) and the latter on 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride or bisphenol A dianhydride (BPA-DA). BPDA is produced by oxidative coupling of inexpensive phthalic acid esters in the presence of palladium catalyst [23, 24]. 

All PEIs derived from 3-aminophenol exclusively formed only isotropic melts. Thermotropic character was however observed in PEIs derived from 4-aminophenol and diphenylether 3,3, 4,4 -tetracarboxylic acid, but not when diphenyl sulphone or isopropylidene diphenyl units were employed. PEIs formed from 4-aminophenol and biphenyl-3,3, 4,4 -tetracarboxylic anhydride have also been found to form nematic melts [37]. 

Kricheldorf also reported the synthesis of a thermotropic polyetherimide based on biphenyl-3,3, 4,4 - tetracarboxylic anhydride, and a, -bis(4-ami-nophenoxy) alkane. He similarly observed the need for aromatic rings additional to the two in the anhydride. Batonet and fan-shaped textures indicative of smectic A phases were observed [44] (20). 

Biphenyl-2,3,3, 4 -tetracarboxylic dianhydride, 476 Biphenyl-3,3, 4,4 -tetracarboxylic dianhydride, 476 Biphenyltetracarboxylic dianhydride, 476... 

The first patent of Edwards and Robinson147 claims the condensations of pyromel-litic acid and aliphatic diamine salt to prepare polyimide. Recently, that approach has been revisited, and biphenyl tetracarboxylic and pyromellitic acids give a salt monomer by reaction with 1 mol of an aliphatic diamine (octamethylene diamine and dodecamethylene diamine). The salts were polymerized under 250 MPa at 250°C for 5 h in closed reaction vessels (Fig. 5.32) giving crystalline polymers.148 By reaction of pyromellitic tetraacid with oxydianiline, it has been possible to isolate a monomeric salt. It was polymerized under 30 MPa giving a PMDA-ODA polyimide with water elimination. 

Biaryl derivatives bearing reactive groups have become increasingly important in industry. Uses for this class of compounds are constantly being developed in the production of high performance polymers. Materials such as 3,3, 4,4 -biphenyl-tetracarboxylic dianhydride 1 and 4,4 -biphenol 2 are monomers employed in the manufacture of high performance polyimides or polyesters. Applications for this family of molecules have also been found both in the dye industry and in the pharmaceutical industry. 

Oxidative homocoupling of aromatic and heteroaromatic rings proceeds with Pd(OAc)2 in AcOH. Biphenyl (165) is prepared by the oxidative coupling of benzene [104,105], The reaction is accelerated by the addition of perchloric acid. Biphenyl-tetracarboxylic acid (169), used for polyimide synthesis, is produced from dimethyl phthalate (168) commercially [106], Intramolecular coupling of the indole rings 170 is useful for the synthesis of staurosporine aglycone 171 [107]. 

Starting materials and solvents were purchased from Aldrich Chemical Co. acetonitrile (ACN), N,N-dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP) were obtained anhydrous in Sure/Seal bottles and used as received. The polyamic acid of PMDA-ODA (2545 Pyralin) was supplied by DuPont. The soluble polyimide XU-218, derived from 3,3, 4,4 -benzophenone tetracarboxylic dianhydride (BTDA) and diamino-1,1,3-trimethyl-3-phenylindan isomers (DAPI) was purchased from Ciba-Geigy Corp. The acetylene terminated imide oligomer powder (Thermid MC-600) derived from BTDA, aminophenylacetylene, and 1,3-bis (2-aminophenoxy) benzene (APB) was obtained from National Starch and Chemical Company. Kapton Type II (PMDA-ODA) films were obtained from DuPont Co., Apical polyimide films were obtained from Allied Corp., and Upilex Type-S and Type-R polyimide films derived from 3,3, 4,4 -biphenyl tetracarboxylic dianhydride (BPDA) plus p-phenylenediamine (PDA) and ODA, respectively were obtained from ICI Americas Inc. 

IR spectroscopy may be used to follow two reactions occurring in polyimides exposed to high temperatures and humidities hydrolysis of the imide linkages and hydrolysis of residual anhydride end groups. The hydrolytic susceptibilities of several polyimides were measured at 90°C/95% R.H. Polymers based on benzophenone tetracarboxylic acid dianhydride (with either oxydianiline or m-phenylene diamine) appeared to undergo rather rapid hydrolysis initially, but the reaction had essentially halted by the time the measured imide content had decreased by 5-6%. Polymers based on 3,3 ,4,4 -biphenyl tetracarboxylic acid dianhydride (with p-phenylene diamine) and pyromellitic dianhydride (with oxydianiline) showed no significant imide hydrolysis. In all the polymers, the anhydride was hydrolyzed quite readily. 

The polyamic acids were prepared in these laboratories using modifications of a standard preparation (7). Benzophenone tetracarboxylic acid dianhydride (BTDA), benzenetetracarboxylic acid dianhydride (pyromellitic dianhydride PMDA), oxydianiline (ODA), 1,4-phenylenediamine (PDA) and 1,3-phenylenediamine (MPDA) were all obtained from Aldrich Chemical Co. The S -biphenyl tetracarboxylic acid dianhydride (BPDA) was obtained from Ube Chemical Company. The polyamic acids were prepared in N-methylpyrrolidinone (BTDA-ODA, BTDA-MPDA and BTDA with a 1 1 molar ratio of MPDA and ODA) or dimethyl acetamide (BPDA-PDA and PMDA-ODA). 

Table 10. Thermotropic poly(etherimide)s based on biphenyl tetracarboxylic imide...

Diaminodiphenyl sulfone BEYO Chemical Co. 3,3 4,4 -Biphenyl tetracarboxylic Shanghai Logic-Chem Import ... 

C22H14N206 polyamidocarboxylic acid based on 3,3, 4,4 -biphenyl-tetracarboxylic dianhydride and para-phenylene diamine 182... 

Neither polyimides derived from 1,2,4,5-benzenetetracarboxylic dianhydride (PMDA) nor from biphenyl tetracarboxylic anhydride with aliphatic spacers have yielded a liquid crystalline phase. The need for an extraring to obtain meso-genic properties was evident. Inoue et al. reported the existence of mesophase in a series of polyimides synthesized from the nylon-salt-type terphenyl tetracarboxylic anhydride with aliphatic diamines (Structure 4) [53-55]. 

PETI-5 3,4 -Oxydianiline, 1,3-bis (3-amino phenoxy benzene) and 3,3, 4,4 -biphenyl tetracarboxylic dianhydride encapped with 4-phenylethynyl pthalic anhydride Phenyl ethynyl 270/250 [141-143]... 

Biphenyl tetracarboxylic add dianhydride/phenylene diamine (BPDA-PDA) polyamic acid, 14.5% solids in N-methylpyrrolidone (NMP), TEF SOB, 60%... 

Poly(amide imide) of biphenyltetracaiboxylic dianhydride PoIy(3,3, 4,4 -benzophene tetracarboxylic dianl dride) Poly(3,3, 4,4 -biphenyl tetracarboxylic dianhydride) Poly(2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane... 

Pyrido[2,l-/][l,2,4]triazine-5,6,7,8-tetracarboxylic acid, 4,4a-biphenyl-l-p-tolyl-synthesis, 3, 428 Pyridotropylium cations... 

Dibenzothiophene acts as a 7r-electron donor and readily forms complexes with known electron acceptors. In such cases the electronic spectrum of a solution of the two compounds shows a new absorption band, usually in the visible region. The order of donor strengths of several o,o -bridged biphenyls has been estimated from their respective charge-transfer spectra and found to be carbazole > fluorene > dibenzothiophene >dibenzofuran. Dibenzothiophene forms complexes with tetracy-anoethylene, various polynitro derivatives of fluorenone, > naphthalene-1,4,5,8-tetracarboxylic acid dianhydride, and tetra-methylmic acid. ... 

Other popular scaffolds have been derivatives of biphenyls which are now readily prepared using solid phase methods [265,464-469]. A solution phase approach has been to react a polyfunctional ised core containing reactive groupings - acid chlorides or isocyanates are easily prepared examples -with a mixture of reagents. One of the earliest synthetic examples showed the use of cubane tetracarboxylic acid chloride [151]. Two recent methods have used functionalised xanthene (library 71) [470] or diphenylmethane cores (library 72) [471] to identify DNA and urokinase receptor antagonists respectively. 

In connection with their synthetic approach to the study of axial pseudoasymmetry, Prelog and co-workers (81) systematically desymmetrized the D2d symmetry inherent in biphenyl-2,2, 6,6 -tetracarboxylic acid (Figure 15) by converting the four functional groups to proper AS units. In principle this is identical with the desymmetrization of spiro [4.4] nonane (Figure 8), which was shown to afford four symmetries D2, S4, C2, and Cj. The desymmetrization (81) was achieved by amidation with optically active a -phenylethylamine. It should be noted that the interesting compound (-)-64, m.p. 140°C of D2 symmetry, which was prepared simply by amidation with the (-)-(5)-amine, possesses no axial chirality. 

Figure 15. Schematic representation of the diastereomers generated by desymmetrization of biphenyl-2,2, 6,6 -tetracarboxylic acid with enantiomeric o-phenylethylamines.

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