4,4 - dibenzoic acid

Note, however, that k depends on the interaction of the proton with the other two charges on the two carboxylate groups. Hence, it is different from k of benzoic acid see Section 5.9. Similarly, k i depends on the interaction with the third carboxylate group—hence it differs from for 1,3-dibenzoic acid. 

The polyester made by reacting hydroquinone with terephthalic acid also melted above 500°C. That from bis-phenol A and 4,4 -(2,2-butylidene)dibenzoic acid is said to be stable in nitrogen to above 400°C. 

Dibenzoic acid chromium is reported as produced when the mixture formed in the preparation of dibenzene chromium by the Grignard reaction is treated with carbon dioxide (227). Substitution reactions for the hydrogen atoms in the rings of the complex, such as are known to occur readily for ferrocene, do not occur in this case (90). 

PPE/PA and a compatibilizer acid chloride of trimeUitic, terephthalic, or l-acetoxyacetyl-3,4-dibenzoic acid Aycock and Ting, 1986, 1987, 1994... 

The tolyl group in glycouril cyclic ether 166 is oxidized with KMn04 in water to give the dibenzoic acid compound 167. Ureidoalkylation of 167 with /> 7ra-methoxybenzene affords the dibenzoic acid-functionalized compound 168 in 81% yield (Scheme 25) <2003JOC9040>. 

Fig. 13. Properties of Injection Molded 4,4 (Alkylenedioxy) Dibenzoic Acid Polyesters.

Figure 9.17 Synthesis of 3 -(4-Phenyl-4H-1,2,4-tria-zole-3,5-diyl) dibenzoic acid [100].

Phenyl-4H-l,2,4-triazole-3,5-diyl) dibenzoic acid has been synthesized as shown in Figure 9.17. 

Photoisomerization of azobenzenes has been widely developed as photochromic compounds. Lots of papers sriU appeared in this subject from basic chemisty to applications. Some examples were described. Harada et al., reported the effect of cyclodextrin derivatives bearing photo-isomerized stilbene moiety. Single molecule conductance of E- and Z-4, 4 -(ethane-l,2-diyl)dibenzoic acids (E-l and Z-1) was determined using scanning tunnelling microscopy (STM). The dynamics of photoisomerization of E- and Z-urocanic acids (E- and Z-2) driven by Hg-free... 

Suegusa et al. first synthesized two organosoluble fluorine-containing aromatic PBIs by direct polycondensation of 4,4 -(hexafluoroisopropylidene) dibenzoic acid (HFA) with 3,3 -DAB and 1,2,4,5-benzenetetra-mine tetrahydrochloride in PPMA or PPA (Figure 5.3) [3]. PPMA was used as a solvent and reaction of a 1 mmol scale, 5 mL of PPMA was found to be appropriate. An optimized reaction solution concentration was required because the polycondensation reaction did not proceed homogeneously at high concentration. 

Benicewicz et al. synthesized another perfluo-rocyclobutane-containing PBI (PFCB-PBl) from 4,4 - [(1,2,3,3,4,4-hexafluorocyclobutane-1,2-diyl) bis(oxy)]dibenzoic acid (PFCB-diacid) and DAB in PPMA (Figure 5.7) [37]. PPA was not used as a reaction medium because the PFCB-diacid monomer was less soluble in PPA and sublimation of PFCB-diacid... 

Y. Saegusa, M. Horikiri, S. Nakamura, Aromatic polybenzimidazoles from 4,4 - (hexa-fluoroisopropylidene)dibenzoic acid and... 

A typical preparation protocol is shown in Scheme 2.146. In the first step in a one-pot reaction, 2,2 -[(l ,l )-hydrazine-l,2-diylidenebis(methanylylidene)] dibenzoic acid is reacted with 1,2-diphosphinobenzene and succinyl chloride to create the racemic bisdiazaphospholane with moderate yield. After condensation of all four carboxylic groups with an optically pure amine, diastereomeric amides are formed, which can be finally separated by liquid chromatography. By using phthaloyl chloride in the cyclization step or other enantiopure aryl amines, several analogs are accessible. For the linkage of sterically encumbering or less nucleophilic amines, the route via the corresponding acyl fluorides proved to be more successful [65]. 

Instead of attaching a large substituent, phenyl, to the hydroquinone molecule to reduce the high melting points of hydroquinone terephthalate polyesters, flexible aliphatic components can be incorporated in the polymer chain. In our earlier paper,we noted that the polyester of 4,4 -(ethylenedioxy)dibenzoic acid and hydroquinone (II, n=2, R=H) melted at... 

C24H14F leOj 4,4 -oxy-dibenzoic acid bis-(lH,l H H-octafluoro-pentyl) ester 424-46-4... 

The preparation of 1,2-dibenzoic acids catalyzed by Pd(II) can be accomplished via directed C—H carbonylation followed by the in situ hydrolysis of an intermediary cyclic anhydride. Electron-rich substituted benzoic acids performed better overall with respect to yield and rate with the ortAo-directed C—H functionalization occurring more efficiently. Strongly electron-withdrawing groups on the aromatic ring render such substrates difficult with this protocol. 

Liang, Z., Jiang, X., Xu, H., Chen, D., Yin, J., Polybenzimidazoles (PBIs) derived from non-coplanar dibenzoic acid containing imidazole (IDBA) Synthesis, characterization and properties, AfocromoZ. Chem. Phys. 2009, 210,1632-1639. 

Poly(methylene oxide) see Poly(oxymethylene) Poly(4,4-(2,7-napthalenedioxy) dibenzoic acid) Poly(oxacyclobutane) see Poly(oxytrimethylene) Poly(oxetane)s see Poly(oxytrimethylene)s Poly(oxy-2-acetoxytrimethyleneoxy-2,6-dichloro-... 

The growth of demand for benzoic acid is expected to increase at a rate of between 1 and 2% per year (17). Glycol dibenzoate plasticizers have been growing at close to 10% annually for the past several years, in part due to environmental concerns with regard to phthalate plasticizers (qv). The growth of the diet soft drink market has increased the demand for sodium and potassium benzoates (17). 

The bulk of this benzoic acid production capacity is consumed internally by the producers. Kalama and Chatterton convert over half of their production to phenol. A large portion of Velsicol s benzoic acid production is utilized in the manufacture of glycol dibenzoate plasticizer esters. 

The largest use for benzoic acid is as a chemical raw material in the production of phenol, caprolactam, glycol dibenzoate esters, and sodium and/or potassium benzoate. 

H-Dibenzo[b,e]thiin-9-carboxylic acids as fungicides, 3, 941 10H-Dibenzo[b,e]thiinium salts reactions... 

Of the many methods which have been published so far for the substitution of existing crowns, probably the most straightforward are Friedel-Crafts alkylation or acylation reactions. Cygan, Biernat and Chadzynski have reported the successful di-t-butylation of dibenzo-24-crown-8 using t-butanol as alkylating agent s . The crown was heated at 100° for 4 h in the presence of excess t-butanol and 85% phosphoric acid. The product was obtained as a crystalline (mp 52—74°) solid in 93% yield. The alkylated crowns are presumably a mixture of isomers substituted once in each ring as illustrated in Eq. (3.14). 

HjO), a picrate, m.p. 253° (dec.) and furnishes a dibenzoate, whose sulphate has [a] ° + 52-1° (EtOH) and hydrochloride, B. HCl. 2H2O, m.p. 115° or 205° (dry), + 41-8° (dilute alcohol) and nitrate, B. HNO3, m.p. 197°. On reduction with hydriodic acid and red phosphorus the dihydroxytropane is converted into tropane and on treatment with phosphorus oxychloride it yields a base, CgHjgON, b.p. 188°/752 mm., picrate, m.p. 177° (dec.). This dihydroxytropane is probably represented by formula (XIII).The dibenzoyl-derivative has local ansesthetic properties. The wovaleryl ester is the alkaloid valeroidine found in Duboisia myoporoides (p. 90). 

Oxime 26 was prepared from 5,ll-dihydro-dibenzo[a,d]cyclohepten-10-one. The Hoch-Campbell reaction of 26 with 3-dimethylaminopropylmagnesium bromide produced aziridine 27 in 46% yield after acidic workup. Extension of the Hoch-Campbell reaction to steroids has also been reported. Thus, treatment of 3(3-hydroxy-5-pregnen-20-one oxime (28) with methylmagnesium iodide furnished a mixture of diastereomers, 20ot/20P,21-imino-20-methyl-5-pregnen-3P-ol (29) in a 50% combined yield and a 3 1 ratio. On the other hand, homo-adamantan-4-one oxime (30) was transformed to homo-adamantano[4,5-b]-2 -ethylaziridine (31) in 76% yield upon the action of... 

---