4,4 -Bis 3,4-dicarboxyl

A synonym for 4,4 -bis(3,4-dicarboxyl phenox5 henyl)-isopropylid-ene dianhydride is Bisphenol A dianhydride. The synthesis of a wide variety of other dianhydride compounds is detailed in the literature. Modifiers for PI are shown in Figure 15.2. 

Bis(3,4-dicarboxyl-phenoxy)benzene dianhydride, 477 4,4 -Bis(3,4-dicarboxyl phenoxyphenyl)-isopropylidene dianhydride, 476, 477 4,4 -Bis(2,3-dicarboxyphenoxy)diphenyl sulfone dianhydride, 489 4,4 -Bis(3,4-dicarboxyphenoxy)diphenyl sulfone dianhydride, 489... 

Poly(amide)s (PA)s that bear the sulfone group in the backbone have been described." These types of PA, which are based on 4,4 -bis-((3-carboxy-phenoxy)(p-benzoyl))-phenyl sulfone, c.f. Figure 7.7, or the corresponding 4-carboxy acid component" is amidized by an aromatic diamine, e.g., p-diaminobenzene. The direct polycondensation of a dicarboxylic acid with aromatic diamines uses triphenyl phosphite and pyridine. The introduction of m-structures increases the solubility of the polymers and leads to... 

Bis(3,4-diethyl-2-pyrrolylmethyl)-3,4-dietliyl-l//-pyrrole (2), prepared in situ from the di-t-butylester of the 5,5 -dicarboxylic acid (/), reacts with 4//-1,2,4-triazole-3,5-dialdehyde (3) in di-chloromethane in the presence of trifluoroacetic acid and 2,3-dichloro-5,6-dicyano-/)-benzoquino-ne as an oxidation reagent. Dark blue crystals are obtained after chromatographic purification. The dark violet chloroform solution fluoresces purple at 360 nm and gives the NMR experiments 39. Which compound and which tautomer of it has been formed ... 

For example. 2-ethoxyindole (1 a) with the alkyne diester in refluxing dioxane yields dimethyl 2-ethoxy-3//-l-benzazepine-3,4-dicarboxylate (2) as a minor product along with a 50 % yield of a mixture of the cis- and tran.v-indol-3-ylacrylates 3.20 However, with 2-ethoxy-l-methylindole (1 b) the l//-l-benzazepine 4 becomes the major product. An analogous reaction with l,2-bis(trifluoromethyl)acetylene to yield 2-ethoxy-l -methyl-3,4-bis(trifluoroiriethyl)-1 //-1-benzazepine has been performed however, the yield was not reported.142... 

Reaction of 3-amino-4-imino-47/-pyrido[l,2- ]pyrazines 319 with DMAD and maleimides 321 yielded 2,2 -bipyr-idine-3,4-dicarboxylates 320, and mixtures of bi- and tricyclic derivatives 322 and 323, respectively (Scheme 27) <1996JPR430>. In the cases of maleimide reactions, higher temperature (at 160°C in xylene) in an autoclave gave only 323. When pyrido[l,2- ]pyrazine 319 (Ar = 4-MeC6H4) was reacted with W-(4-methylphenyl)-maleimide 321 (R = 4-MeC6H4), 324 could be isolated. 

The reactions of diazoesters with hydrochloric and sulfuric acids, triphenylphosphine, and dinitrogen tetroxide resulted in aryl chloroacetates, bis(aryloxycarbonylmethyl) sulfates, triphenylphosphoranylidenehydrazones of aryl 2-oxoethanoates, and iV-oxides of diaryl l,2,5-oxadiazole-3,4-dicarboxylates <1999RJO 666>. 

The BASF route started from hydroquinone, which was converted to 2,5-dihydroterephthalic acid by a Kolbe-Schmitt reaction. One mole of this acid was treated with two moles of an arylamine, both components being in the form of a suspension in aqueous methanol. This was added to a small amount of a solution of vanadium(III) chloride and sodium chlorate. Gentle heating gave a 95% yield of 2,5-bis(arylamino)benzo-l,4-quinone-3,6-dicarboxylic acid. Ring closure to the trans-quinacridonequinone took place in the presence of concentrated sulphuric acid at 60-80 °C. This was then reduced to the required crude pigment by zinc or aluminium powder in caustic soda under pressure,in an aluminium chloride/urea melt or by the use of a sulphuric acid/polyphosphoric acid mixture. 

In a [2 + 2] cycloaddition example, 1,2-dichloroethene was reacted with readily available dimethyl 7,8-bis(trifluoromethyl)-9-oxatricyclo[4.2.1.02 5]nona-3,7-diene-3,4-dicarboxylate in a photochemical reaction, from which dimethyl 4,5-dichloro-9,10-bis(trifluoromethyl)-ll-oxa-tetracyclo[6,2.1.02 7.03,6]undec-9-ene-3,6-dicarboxylate (22) was isolated in 72% yield.29... 

Sulfur tetrafluoride fluorination of the methyl group has been reported.253 Thus, the reaction with 2,5-dimethylfuran-3,4-dicarboxylic acid gives, besides the expected acid fluoride 16 and 2,5-dimethyl-3,4-bis(trifluoromethyl)furan (17a), higher fluorinated compounds, 2-(difluoro-methyl)-5-methyl-3,4-bis(trifluoromethyl)furan (17b) and 2-methyl-3,4,5-tris(trifluoromethyl)-furan (17c). Low yields are due to considerable tar formation. 

Substance B In the structure below, R = CH(CH3)2. The systematic compound name is bis (l-methylethyl)-2,6-dimethyl-4-(3-nitrophe-nyl),l,4-dihydro-pyridine-3,5-dicarboxylate. 

Catena-((4-nitropyrazole-3,5-dicarboxylic acid)-bis(dioxane)-sodium) 1.347 1.341 1.386 1.363 1.339... 

More interestingly perhaps, the polyketone 7, derived from bis(4-phenoxyphenyl)-p-carborane (3) and biphenyl-4,4 -dicarboxylic acid (4), is essentially amorphous on isolation from trifluoromethanesulfonic acid, but crystallises on heating above its glass transition temperature (267 °C) before finally melting at around 390 °C. 

When heated to 100-110"C, the bis(phenylhydrazide) of pyridine-3,4-dicarboxylic acid cy-clized with loss of one molecule of phenylhydrazine to give 2- or 3-phenylpyrido[3,4-(/]-pyridazinc-1,4(2/7,37/)-dione.118 With 2-methyl-6-(4-tolyl)pyridine-3,4-dicarbohydrazide, cy-clization to the corresponding pyrido[3,4-c/]pyridazine-l,4(2/7,3//)-dione 3 occurred by refluxing with hydrazine in ethanol the product was isolated as the hydrazinium salt.119... 

The independent observations of Neunhoeffer and Lehmann69 and Gompper and Heinemann70 that dimethyl acetylenedicarboxylate is sufficiently reactive to participate in an apparent Diels-Alder reaction with dimethyl 2,6-bis(dimethylamino)pyridine-3,4-dicarboxylate represents the first evidence that pyridine systems appropriately substituted with strong electron-donating groups (pyridyl C-2/C-6) may function as a 2-azadiene system in [4 + 2] cycloadditions with reactive, electron-deficient dienophiles [Eq. (13)]. 

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