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Hydrogenation of fumaric acid

Figure 3.2b, The effect of pH on the initial rate of hydrogenation of fumaric acid (FA) catalyzed by [RhCl(TPPMS>3] in aqueous solution. [Rh]=5.2 x lO" M, [FA1=0.05 M, 60 C, Hi, 1 bar total pressure. The calculated distribution (a%) of nondissociated (H A) and dissociated (HA , fumaric acid is also shown. Reprinted with permission from Chem. Eur. J. 2001, 7, 193. Copyright (2001) Wiley-VCH Verlag GmbH. Figure 3.2b, The effect of pH on the initial rate of hydrogenation of fumaric acid (FA) catalyzed by [RhCl(TPPMS>3] in aqueous solution. [Rh]=5.2 x lO" M, [FA1=0.05 M, 60 C, Hi, 1 bar total pressure. The calculated distribution (a%) of nondissociated (H A) and dissociated (HA , fumaric acid is also shown. Reprinted with permission from Chem. Eur. J. 2001, 7, 193. Copyright (2001) Wiley-VCH Verlag GmbH.
Ruthenium (II) Chloride. The homogeneous catalysis of the hydrogenation of fumaric acid in aqueous solution by ruthenium (II) chloride has been interpreted (36) in terms of the following mechanism in which the heterolytic splitting of H2 by a Ru -olefin complex is the rate-determining step. [Pg.9]

Early experiments concerned the enzymatic hydrogenation of fumaric acid to succinic acid, catalyzed by either yeast 24,55 or enzyme extracts from yeast cells56. Much later, strains of Escherichia coli, Aerobacter aerogenes and Aerobacter cloacae were shown to have the same ability 57,58. An interesting mixed culture fermentation has been developed, where the fungus Rhizopus chinensis produces fumaric acid from glucose and a selected E. coli converts the previously formed fumaric acid into succinic acid58. [Pg.1078]

VM Fig. 27.13 (a) Catalytic cycle for the hydrogenation of fumaric acid by [H4(r -C6H6)4Ru4] (b) H4RU4 core of... [Pg.922]

Hydrogenation of allyl alcohol In the solvents water and ethanol and In the presence of Raney nickel catalyst Hydrogenation of fumaric acid In the solvent ethanol and In the presence of Raney nickel catalyst Hydrogenation of aniline to cyclohexylanlllne by nickel catalysts Hydrodesulfurization of narrow-boiling-range fractions of gas oil... [Pg.681]

Racemic acid, ( )-tartaric acid, is a compound of the two active forms. M.p. 273 C (with IHjO), m.p. 205°C (anhydrous). Less soluble in water than (-t-)-tartaric acid. Formed, together with mesotartaric acid, by boiling (4-)-tartaric acid with 30% NaOH solution, or by oxidation of fumaric acid. Potassium hydrogen racemate is very insoluble. [Pg.385]

Figure 6-18 shows a bell-shaped pH-rate profile for the hydrolysis of monomethyl dihydrogen phosphate. Other examples are the hydrolysis of o-carboxyphenyl hydrogen succinate and the hydration of fumaric acid. ... [Pg.291]

Hydrogen. The Synthesis and Oxidation of Fumaric Acid. J. Amer. chem. Soc. 64, 948 (1942). [Pg.177]

The oxidation of fumaric acid with hydrogen peroxide in the presence of sodium tungstate was used to prepare this intermediate and the product isolated in 60% yield. [Pg.472]

Figure 10-9 Representation of the course of enzyme-induced hydration of fumaric acid (trans-butenedioic acid) to give L-malic acid (L-2-hydroxy-butanedioic acid). If the enzyme complexes with either—C02H (carboxyl) group of fumaric acid, and then adds OH from its right hand and H from its left, the proper stereoisomer (l) is produced by antarafacial addition to the double bond. At least three particular points of contact must occur between enzyme and substrate to provide the observed stereospecificity of the addition. Thus, if the enzyme functions equally well with the alkenic hydrogen or the carboxyl toward its mouth (as shown in the drawing) the reaction still will give antarafacial addition, but o,L-malic acid will be the product. Figure 10-9 Representation of the course of enzyme-induced hydration of fumaric acid (trans-butenedioic acid) to give L-malic acid (L-2-hydroxy-butanedioic acid). If the enzyme complexes with either—C02H (carboxyl) group of fumaric acid, and then adds OH from its right hand and H from its left, the proper stereoisomer (l) is produced by antarafacial addition to the double bond. At least three particular points of contact must occur between enzyme and substrate to provide the observed stereospecificity of the addition. Thus, if the enzyme functions equally well with the alkenic hydrogen or the carboxyl toward its mouth (as shown in the drawing) the reaction still will give antarafacial addition, but o,L-malic acid will be the product.
The simplest unsaturated dicarboxylic acids are maleic acid and fumaric acid, both of which are cheap, commercially available, materials. They are geometric isomers maleic acid is the (Z) isomer (19), and fumaric acid is the (E) isomer (20). Maleic acid forms an internal anhydride, maleic anhydride (21), which is widely used to form adducts with conjugated dienes (the Diels-Alder reaction, Section 7.6). The formation of the anhydride from maleic acid and the conversion of maleic acid into fumaric acid are described in Expt 5.218. The hydrogenation of maleic acid to succinic acid is of value as a means of evaluating the activity of a catalyst for use in hydrogenations at atmospheric pressure the experimental procedure is given in Section 2.17.1, p. 87. [Pg.805]

When ketotifen hydrogen fumarate was shaken with D 0, the carboxylic group protons of fumaric acid and the N+H protons were exchanged for deute-rons from D 0, as shown by the absence of the broad peak at 9.1 ppm (see Table 4.) (5). [Pg.247]

Potentiometric titration of fumaric acid fifty mg of ketotifen hydrogen fumarate with 2.5 HqO was weighed (io.l mg) into a titration vessel and dissolved in lo ml of ethanol and lo ml of water (5). The resulting solution was titrated potentiometrically with o.l M NaOH is equivalent with 5.8 mg of fumaric acid. The content of fumaric acid in the sample is calculated by using equation (2) ... [Pg.260]

A solution of the above compound in a mixture of ethanol (20 ml) and acetic acid (20 ml) is shaken with a 30% palladium-on-charcoal catalyst (0.1 g) in an atmosphere of hydrogen at laboratory temperature and pressure until 250 ml of hydrogen is absorbed. The mixture is filtered, the filtrate is evaporated to dryness under reduced pressure and to the residue is added a hot solution of fumaric acid (1.25 g) in ethanol (15 ml). The mixture is kept at 5°C for 12 hours and is then filtered, and the solid residue is washed with hot ethanol and then dried. There is thus obtained l-p-hydroxyphenoxy-3-beta-(morpholinocarbonamido)ethyl-amino-2-propanol hydrogen fumarate, m.p. 168-169°C (with decomposition). [Pg.3468]

The crystal of (—)-(fumaric acid)Fe(CO)4 contains three crystallo-graphically distinct complex molecules. A, B, and C, each of which has C2 symmetry (139). As in the racemate, the four carbon atoms of the fumaric acid are not coplanar, but show dihedral angles of 151°, 148°, and 146° in molecules A, B, and C, respectively. Although the axis of the double bond in molecules A and C is significantly tilted out of the equatorial plane of the complex, that of molecule B is not. The different coordinations are presumably stabilized by different arrangements of the hydrogen bonds (139). [Pg.247]

The hydrogenation of acetylenedicarboxylic acid dimethyl ester (80) and diphenylacetylene (83) with [RhH2(0C(==0)0H)(PPr 3)2] gives dimethyl fumarate (82) and fraws-stilbene (84), respectively. This complex also catalyzes an isomerization of ds-stilbene to fra s-stilbene, though hydrogenation of alkyne is about eight times faster than the isomerization. ... [Pg.458]

In contrast to the case of maleic and fumaric acids, hydrogenation of crotonic acid was sharply inhibited by an excess of TPPMS - again, behavior analogous to that of [RhCl(PPh3)3] in hydrogenation of alkenes. [Pg.436]


See other pages where Hydrogenation of fumaric acid is mentioned: [Pg.4]    [Pg.800]    [Pg.264]    [Pg.958]    [Pg.4]    [Pg.800]    [Pg.264]    [Pg.958]    [Pg.85]    [Pg.40]    [Pg.69]    [Pg.70]    [Pg.103]    [Pg.516]    [Pg.363]    [Pg.97]    [Pg.97]    [Pg.643]    [Pg.49]    [Pg.294]    [Pg.68]    [Pg.437]    [Pg.61]    [Pg.62]    [Pg.63]    [Pg.181]    [Pg.189]    [Pg.219]   
See also in sourсe #XX -- [ Pg.799 , Pg.800 ]

See also in sourсe #XX -- [ Pg.922 ]

See also in sourсe #XX -- [ Pg.958 ]




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