Trimesic acid

J. Rebek, Jr., (1987) first developed a new synthesis of Kemp s acid and then extensively explored its application in model studies. The synthesis involves the straightforward hydrogenation (A. Steitz, 1968), esterification and methylation of inexpensive 1,3,5-benzenetricar-boxylic acid (trimesic acid 30/100 g). The methylation of the trimethyl ester with dimethyl sulfate, mediated by lithium diisopropylamide (V. J. Shiner, 1981), produced mainly the desired aff-cis-1,3,5-trimethyl isomer, which was saponified to give Kemp s acid. 

Reimschuessel and Deget polymerized caprolactam in sealed tubes containing about 0.0205 mol HjO per mole caprolactam. In addition, acetic acid (V), sebacic acid (S), hexamethylene diamine (H), and trimesic acid (T) were introduced as additives into separate runs. The following table lists (all data per mole caprolactam) the amounts of additive present and the analysis for end groups in various runs ... 

See Trimesic acid. [PHTHALIC ACID AND OTHERBENZENEPOLYCARBOXYLIC ACIDS] (Vol 18)... 

Phthahc anhydride (1) is the commercial form of phthaUc acid (2). The worldwide production capacity for the anhydride was ca 3.5 x 10 metric tons ia 1993, and it was used ia the manufacture of plasticizers (qv), unsaturated polyesters, and alkyd resins (qv) (see Polyesters, unsaturated). Sales of terephthahc acid (3) and its dimethyl ester are by far the largest of any of the benzenepolycarboxyhc acids 14.3 x 10 t were produced in 1993. This is 80% of the total toimage of ah. commercial forms of the benzenepolycarboxyhc acids. Terephthahc acid is used almost exclusively for the manufacture of poly(ethylene terephthalate), which then is formed into textiles, films, containers, and molded articles. Isophthahc acid (4) and trimehitic anhydride (5) are commercial products, but their worldwide production capacities are an order of magnitude smaller than for terephthahc acid and its dimethyl ester. Isophthahc acid is used primarily in the production of unsaturated polyesters and as a comonomer in saturated polyesters. Trimehitic anhydride is used mainly to make esters for high performance poly(vinyl chloride) plasticizers. Trimesic acid (6), pyromehitic dianhydride (7), and hernimehitic acid (8) have specialized commercial apphcations. The rest of the benzenepolycarboxyhc acids are not available commercially. 

Trimesic acid is also referred to as 5-carboxyisophthahc acid [554-95-0] trimesinic acid, or trimesitinic acid. It is a smaH-volume, synthetic chemical and is sold commercially. Traces of trimesic acid as well as other aromatic carboxyUc acids with three or more carboxyUc acid groups are found in lignite (137), and when various types of coals or coal components such as brown coal, asphaltene, or coal-tar pitch are oxidized. 

Manufacture. The only current U.S. manufacturer of trimesic acid is Amoco Chemical Co. It is produced by oxidation of mesitylene (1,3,5-trimethylbenzene) via the Hquid-phase oxidation in acetic acid using the cobalt— manganese—bromine catalyst system (138). This is a variant of the system used to produce terephthaUc and isophthaUc acids as well as trimellitic anhydride. American Bio-Synthetics Corp. did produce it by batch oxidation of mesitylene with potassium permanganate. 

Economic Aspects. Trimesic acid being a smaH-volume chemical, availabiUty is in polyethylene-lined fiber dmms in 34- and 136-kg quantities. Mesitylene [108-67-8] the raw material, is readily available, and oxidation to trimesic acid presents no problems. The market size is dictated by commercial uses. 

Specifications and Standards. Table 35 Hsts specifications for trimesic acid as produced by Amoco Chemical (139). Typically, the product is over 98% pure. 

Amoco Trimesic Acid," Bulletin FM-1, Amoco Chemical Co., Chicago, lU. 

Liquid-phase air oxidation of mesitylene with Co, Mn, and Bt catalysis produces 1,3,5-benzenetricarboxyhc acid [554-95-0] (trimesic acid) (10) (37) as does the oxidation with dilute nitric acid (qv). Amoco has oxidized mesitylene to trimesic acid on a small scale (see Phthalic acid and other BENZENECARBOXYLIC acids). Less vigorous stepwise oxidation of mesitylene can yield 3,5-dimethylbenzoic acid [499-06-9] (11) and 5-methyhsophthahc acid... 

Since the FeCp(C6H6)+ unit is robust towards oxidation even in concentrated sulfuric acid, oxidation of alkyl substituents upon boiling in aqueous KMn04 solution can be achieved and leads to carboxylic substituents. The mesitylene complex can be oxidized to the mono-, di-, or tri-carboxylic add depending upon the reaction conditions. In the latter case, the decomplexed trimesic acid is obtained [106, 107] Scheme XXII ... 

Examples of crystalline associates where dimethyl sulfoxide is involved as one of the heteromolecular constituents are known in an appreciable number1. Certainly the associate between dimethyl sulfoxide and trimesic acid 84 (cf. Chapter 5 in Vol. 140 of this series) is one of the important individual cases. Characteristic modes of association between the carboxylic hosts discussed here and dimethyl sulfoxide are illustrated in Fig. 24. Pertinent geometry data are listed in Tables 17 and 18. One may realize from Fig. 24 that the fundamental mode of association of the host acids 20, 26, 37, and 41 is the formation of discrete H-bonded islands of host and (usually) one guest molecule. 

In our group, several dendrimers based on ( R)-3-hydroxybutanoic acid (HB) have been prepared [56-58]. The dendrimers were synthesized by the convergent strategy. Trimesic acid has been used as core unit and the benzyl esters of the dimer and the tetramer of HB as elongation units. In such a way dendrimers of 1st and 2nd generation (27-30) have been constructed (Fig. 13). Since poly(.R)-3-hydroxybutanoic acid (PHB) is known to be biodegradable [59, 60] the stability of the dendrimers 27-30 was tested in the presence of PHB-de-... 

Trimellitic anhydride, b32 Trimesic acid, b31 Trimesoyl chloride, b33 T rimethoxymethy lsilane, m455 Trimethylacetaldehyde, d677... 

Examples of other organic materials prepared by mechanochemical procedures, for which stmcture determination has been carried out directly from powder XRD data, include a hydrate cocrystal of 5-methyl-2-pyridone and trimesic acid, which was prepared by grinding a methanol solvate cocrystal of the same components... 

Potential-induced phase transition of trimesic acid on Au(lll) electrode has been studied using in situ STM and CV [325]. In cyclic voltammograms, a pair of peaks was formed, which was ascribed to the structural transformation. On the basis of high-resolution STM images in 0.1 M HCIO4, it has been proposed that trimesic acid molecules assume flat-lying and vertical orientations at 0.25 V and 0.85 V, respectively. Both orientations coexisted at 0.65 V. 

Organic azides with initiating properties may be exemplified by the following substances (Curtius [148]) oxamidoazide (III) and triazide of trimesic acid (IV) ... 

The first of these is obtained by the action of nitrous acid on oxamidohydrazide. It is unstable and decomposes explosively at 115°C. The second is formed by the action of nitrous acid on the trihydrazide of trimesic acid. The explosive properties of neither of these azides have been reported. 

Benzene-1,3,5-tricarboxylic acid (trimesic acid) [554-95-0] M 210.1, m 360 (dec). Crystd from water. 

Each of the methods had trouble recovering the more highly water-soluble or volatile model compounds such as trimesic acid, furfural, glucose, glycine, caffeine, and methyl isobutyl ketone. Quinaldic acid, an amphoteric substance of moderate water solubility, was also poorly recovered by each method, except for the QXAD-4 procedure. 

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