Cyclobutane tetracarboxylic

Poly(amic acids) were prepared by the ambient temperature condensation of 1,2,3,4-cyclobutane tetracarboxylic dianhydride with selected aromatic diamines. When the poly(amic acids) and liquid crystal alignment agents y-butyrolactone and A-methyl-pyrrolidone were spin-coated and cured onto an inert surface, the polyimide was effective as a liquid crystal aligner. 

A reaction flask was charged with 3,5-di-dodecyloxybenzyl-3,5-diamino-benzoate-diamine (0.75 mmol), 1, 2, 2 -bis[4-(4-aminophenoxy)phenyl]propane (4.25 mmol), 1,2,3,4-cyclobutane tetracarboxylic dianhydride (5.00 mmol), and A-methylpyrrol-idone (17.69 g) and then stirred at ambient temperature until a 15 wt% solid content polyimide precursor solution was obtained. 

TABLE 3. Results of water and methylene/iodine repellency testing of polyimide films obtained by reacting 1,2,3,4-cyclobutane tetracarboxylic dianhydride with amines described in Table 1. 

MacGillivray and co-workers have recently demonstrated that the linear template approach can also be expanded to hydrogen-bond acceptor templates. In particular, co-crystallization of 2,3-bis(4-thiopyridylmethyl)naphthalene as a template with fumaric acid as the reactant produced a finite, four-component molecular assembly held together by O-H N hydrogen bonds (Fig. 2.3.10(a)) [57]. The double bonds of the stacked fumaric acid molecules were aligned suitably for a photodimerization that proceeded, upon UV-irradiation with 300 nm light, in a SCSC fashion to a maximum of 36% yield. The photoreaction provided, stereospecifically, the rctt isomer of 1,2,3,4-cyclobutane-tetracarboxylic acid (Fig. 2.3.10(b)). 

Y. Lu, Z. Hu, Y. Wang, Q.X. Fang, Organosolu-ble and light-colored fluorinated semialicyclic polyimide derived from 1,2,3,4-cyclobutane-tetracarboxylic dianhydride, J. Appl. Polym. Sci. 125 (2) (2012) 1371-1376. 

Figure 6.26 Photodimerization of maleic anhydride (44) to cyclobutane tetracarboxylic dianhydride (45) and the experimental setup for the ultrasound-assisted photodimerization...

Decarboxylation reactions of cyclobutanecarboxylic acids appear to pose no particular problems. Cyclobutane-1,1-dicarboxylic acids can usually be decarboxylated thermally at temperatures up to 200 C.1 5> n 340 For example, cyclobutane-1,1,3,3-tetracarboxylic acid was heated to 185 °C at reduced pressure to give a mixture of cis- and frani-cyclobutane-l,3-dicarboxylic acid (l).1 Noteworthy in this reaction is the stereocontrof obtained in the product due to the formation of the anhydride. Generally, decarboxylation will give a mixture of cis- and transacids. The decarboxylation has sometimes been performed in a distillation step.4,5... 

This reaction was first reported by Perkin in 1883. It is the nucleophilic alkylation between malonic ester and Q, o)-alkyl dihalide to form cyclic aliphatic 1,1-diester or acid and is known as the Perkin reaction or Perkin synthesis. Although it was once referred to as the Perkin condensation, this name should not be used for this type of reaction. Using this protocol, Perkin successfully prepared cyclopropane-, cyclobutane-, cyclopentane-, cyclohexane-, and cycloheptane-1,1-dicarboxylie acids. However, this reaction is often complicated by the side reaction that forms Q, o, a ,a -tetracarboxylic ester from the Sn2 reaction between malonic ester and o, a -alkyl dihalide, this side reaction can be depressed if alcoholic sodium malonic ester is added slowly to the o, a -alkyl dihalide with vigorous stirring. It is interesting that the K2CO3 promoted a reaction between dimethyl 1,3-acetonedicarboxylate and tran5 -l,4-dibromobutene yields vinyldihydrofuran. ... 

O3 passed at room temp, into a suspension of a-truxillic acid in acetic acid-water over a period of 20 hrs., then lO -HgOg-soln. added gradually, and after 2 days the solvent removed in vacuo below 40° crude cyclobutane-1,2/3,4-tetracarboxylic acid. Y 90%. Also isomers s. R. Criegee and H. Hover, B. 93, 2521 (1960). 

Tetraethyl butane-1,1,4,4-tetrtacarboxylate added to a soln. of Na in abs. alcohol, to the resulting soln. tetraethyl l,4-dibromobutane-l,l,4,4-tetracarboxy-late added, and heated 4 hrs. in an oil bath at no-IIS -> tetraethyl cyclobutane-1,1,2,2-tetracarboxylate (Y 75.2%) boiled with aq. HGl (1 1) at ISO-HO in an oil bath until the oily layer has dissolved after 35-40 hrs., the HGl removed by distillation, and the residue heated at 180-200° until G0.2-evolution ceases mixture of cis- and frans-cyclobutane-l,2-dicarboxylic acids (Y 97.5%) refluxed 5 hrs. at 70-90° with acetjd chloride on a water bath, excess acetyl chloride and the resulting acetic acid removed by distillation at atmospheric pressure, and the residue heated 6-7 hrs. at 160-175° in an oil bath whereby the mixed anhydride of frans-cyclobutane-l,2-dicarboxylic acid and acetic acid is converted to acetic anhydride and cis-cyclobutane-l,2-dicarboxylic acid anhydride (Y 81.2%) boiled with 2 parts of water cis-cyclobutane-l,2-di-carboxylic acid (Y ca. 100%). V. P. Gol mov and Z. P. Malevannya, 7K. 31, 665 (1961) G. A. 55, 22162b method of ring closure s. J. J. Lennon and W. H. Perkin, Soc. 1928, 1513. 

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