2- -1,23-propane tricarboxyl

As an example of the quantitative testing of Eq. (5.47), consider the polymerization of diethylene glycol (BB) with adipic acid (AA) in the presence of 1,2,3-propane tricarboxylic acid (A3). The critical value of the branching coefficient is 0.50 for this system by Eq. (5.46). For an experiment in which r = 0.800 and p = 0.375, p = 0.953 by Eq. (5.47). The critical extent of reaction, determined by titration, in the polymerizing mixture at the point where bubbles fail to rise through it was found experimentally to be 0.9907. Calculating back from Eq. (5.45), the experimental value of p, is consistent with the value =0.578. 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

Chemical Designations - Synonyms 2-Hydroxy-l,2,3-Propane-Tricarboxylic Acid beta-Hyd-roxytricarballylic Acid beta-Hydroxytricarboxylic Acid Chemical Formula H0C(CH2C0jH)jC02H. Observable Characteristics - Physical State (as normally shipped) Solid Color White Odor None. Physical and Chemical Properties - Physical State at 15 T7 and 1 atm. Solid Molecular Weight 192.1 Boiling Point at 1 atm. Not pertinent (decomposes) Freezing Point 307, 153, 426 Critical Temperature Not pertinent Critical Pressure Not pertinent Specific Gravity 1.54 at 20°C (solid) Vapor (Gas) Density Not pertinent Ratio of Specific Heats of Vapor (Gas) Not pertinent Latent Heat of Vaporization Not pertinent Heat of Combustion -4,000, -2,220, -93 Heat of Decomposition Not pertinent. 

Citric acid, 2-hydroxy-l,2,3-propane tricarboxylic acid, HOOCCH2C(OH)(COOH)CH2COOH 192.1 152-154... 

SYNS ATEC CITRIC ACID, ACETYL TRIETHYL ESTER CITROFLEX A 2 1,2,3-PROPANE-TRICARBOXYLIC ACID, 2-(ACETYLOXY)-, TRIETHYL ESTER (9CI) D TRICARBALLYLIC ACID, P-ACETOXY-TRIBLnrYL ESTER TRIETHYL ACETYLCITRATE TRIETHYL CITRATE, ACETATE TRIETHYLESTER KYSELINY ACETYLCITRONOVE... 

Citric Acid (2-Hydroxy-1,2,3-propane-tricarboxylic Acid) (Citronensaure or 3 Oxy-propan-tricarbon-saure in Ger), C HgO, mw 192.12 col crysts, mp 153°,bp decomp, d 1.542 at 20/4° sol in w or ale si sol in eth can be obtained from lemon, lime or pineapple juice. It has been used in foods, drinks, medicines NC lacquers, alkyd resins, etc (Refs 1,3 5). Davis (Ref 2) describes its use in prepn of HMTPDA and Zenftman Forlin (Ref 4) patented its use in fuse compns Refs l)Beil 3, 556, (194) [359] 2)Davis (1943), 451 3)Kirk Othmer 4, (1949), 8-23 (A review with 45 refs) 4)H.Zenftman J.Forlin,... 

Citric acid (8) 1,2,3-Propane tricarboxylic acid, 2-hydroxy- (9) (77-92-9)... 

Citric Acid 2-Hydroxy-1,2,3-Propane-Tricarboxylic Acid Beta-Hydroxy-tricarballylic Acid Beta-Hydroxy- tricarboxylic Acid ... 

Problem 5.27 For a system composed of diethylene glycol (2.0 mol), 1,2,3-propane-tricarboxylic acid (0.6 mol), and adipic acid (1.0 mol), determine the number average degree of polymerization before gelation. Derive first a general expression to obtain this. 

Synonyms. P-Carboxyglutaric acid 1, 2, 3-Propane-tricarboxylic acid. 4.7.9.2.S Theory. The synthesis of tricarballylic acid is usually accomplished by means of the following three steps, namely ... 

In the reaction of glycerol, /= 3, with equivalent amounts of several diacids, the gel point was observed [14,15] at an extent of reaction of 0.765. The predicted values of are 0.709 and 0.833 calculated from [13] (Flory, statistical) and [12] (Carothers), respectively. Flory [13] studied several systems composed of diethylene glycol (/=2), 1,2,3-propane-tricarboxylic acid (/ = 3), and either succinic or adipic acid (/ = 2) with both stoichiometric and nonstoichiometric amounts of hydroxyl and carboxyl groups, see Table 1. 

Yakubchik and his co-workers (1956, 1959 and 1962) have preferred to separate the acid derivatives by means of partition chromatography and compared the results with those obtained from an artificial mixture of those acids expected to be present. In the case of Ziegler-Natta catalyzed polybutadienes with less than 1% 1,2- units the presence of 1,4-1,2-1,4 sequences was indicated by the identification of some 1,2,4-butane tricarboxylic acid. Examination of their chromatograms suggests, at most, just a trace of any hexane tetra-carboxylic acid so that only a very small amount, if any, of 1,4-1,2-1,2-1,4 structures were present. Furthermore, no trace of any 1,2,3-propane tricarboxylic acid was found so there was no positive sign of any branching at the a-methylene position. On the other hand in the case of rubidium-catalyzed poly butadienes, which, like other polybutadienes prepared by the use of alkali metal catalyst systems, have a high 1,2- content, both hexane tetracarboxylic acid and 1,2,3-propane tricarboxylic acid were present in the ultimate products of ozonolysis. 

Hydroxy-l,2,3-propane tricarboxylic a-Ionol 10542 Isopentyl cyanide 7556... 

Fig. 2.4 Variation of p, x and rj with time for the polymerization of ethylene glycol with succinic acid and 1,2,3-propane tricarboxylic acid (after Flory).

It is interesting to compare the predictions of the two theories with each other and with what happens in practice. Fig. 2.4 shows the variation of p, x and the viscosity tj with time for a reaction between diethylene glycol (a diol), succinic acid (a diacid) and 1,2,3-propane tricarboxylic acid (a triacid). The mixture was found to gel after about 230 min and this was manifested by tj becoming infinite, pc, is about 0.9 and Jf was only 25 at this... 

The most common poly(alkenoic acid) used in polyalkenoate, ionomer or polycarboxylate cements is poly(acrylic acid), PAA. In addition, copolymers of acrylic acid with other alkenoic acids - maleic and itaconic and 3-butene 1,2,3-tricarboxylic acid - may be employed (Crisp Wilson, 1974c, 1977 Crisp et al, 1980). These polyacids are prepared by free-radical polymerization in aqueous solution using ammonium persulphate as the initiator and propan-2-ol (isopropyl alcohol) as the chain transfer agent (Smith, 1969). The concentration of poly(alkenoic add) is kept below 25 % to avoid the danger of explosion. After polymerization the solution is concentrated to 40-50 % for use. 

Ligands with more that two carboxyl groups do not seem to form more stable complexes than the biscarboxylate ligands. An example is the ligand propane-1,2,3-tricarboxylate (tricarballilate) for which the equilibrium constant for the formation of the complex BeL is little greater than with succinate (76). 

HOOC -CH -CH(COOH)-CH -COOH — Propane-1, 2, 3-tricarboxylic acid... 

Propane-1,2,3-tricarboxylic acid was also used as template for the preparation of artificial siderophores 22 and 23. A structurally similar template, bis(carboxymethylamino) acetic acid, was used to prepare 24. AU three showed identical growth promotion of several strains of E. coli. ... 

The title compound can be prepared by condensing an alkyl a-bromocaprylate with a trialkyl propane-1,1,3-tricarboxylate to give a substituted cyclopentanone. Hydrolysis, decarboxylation, and esterification of the resulting monocarboxylic... 

BenzyU3,5 dioxo 4 pyrazolidineacetyl Azide or a-Phenylpropane-/3,/3,y-tricarboxylic Hydra-zoazide (called a-Phenyl-propan-/3,j3,y-tri-carbonsaure hydraziazid by Curtius),... 

The resulting tetraethyl ester on hydrolysis and decarboxylation yields propane-1, 2,3-tricarboxylic acid.155 In this example the malonate anion is generated by using one molar proportion of sodium ethoxide this is Michael s original method. However, these conditions sometimes lead to competing side reactions and the formation of abnormal reaction products. Better yields of the required product are often obtained with small amounts of sodium ethoxide (the so-called catalytic method) or in the presence of a secondary amine (e.g. diethyl-amine, see below). 

Fumonisins are a group of toxins produced primarily by Fusarium verticil-lioides (formerly called F moniliforme), Eprolifemtum and other related species which readily colonize corn all over the world [120-124]. Nine structurally related fumonisins including Bj, B2, B3, B4, A, and A2, have been described (fig. 8). Chemically, fiimonisin Bj is a derivative (diester) of propane-1,2,3-tricarboxylic acid of 2-amino-12,16-dimethyl-3,5,10,14,15-pentahydroxy-icosane [121-130]. The other fumonisins lack the tricarballylic acid or other ester groups [121, 131, 132]. Fumonisins are chemically similar in structure to toxins (AAL) produced by Altemaria altemata [133]. Production of fumonisins hy Altermria has also been reported [134,135], and some fumonisin-producing Fusaria have been knovm to produce AAL toxins [136]. 

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