Methyl itaconate, preparation

Poly(itaconic acid) has also been prepared in a 0.2M/liter aqueous solution using potassium persulfate at 50 C over a 5-hr period under reduced pressure. After the polymer is reprecipitated twice into methanol-ethyl acetate, a polymer is isolated with a molecular weight of 1.64 x 10, determined by vapor pressure osmometry of a methanolic solution of the methyl ester prepared from the polymer [49]. Unfortunately Tsuchida and coworkers did not report on the quantitative extent to which poly(methyl itaconate) had been formed from this polymer (presumably by reaction with diazomethane). Consequently, there is little in the literature to confirm or dispute the paper by Braun and Azis el Sayed [97], which offered evidence that during the free-radical polymerization of itaconic acid, carbon dioxide evolves to a considerable extent. During the process, it seems that hydroxyl and formyl radicals are generated and incorporated in the macromolecule. It is proposed by these authors that the homopolymer of itaconic acid contains virtually no itaconic acid repeat units but rather intramolecular lactone rings and acetal- or hemiacetal-like moieties. Since the polymer remains soluble in the reaction solvent (dioxane). 

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. ... 

A 1996 work deposited four different catalytic metals on a p-cyclodextrin— epichlorohydrin copolymer to prepare Pd(Pt, Rh, Ru)-P-cyclodextrin copolymer catalysts.8 These were used to catalyze the asymmetric hydrogenations of the C=C bonds of trans-2-methyl-2-pentenoic acid, and dimethyl itaconate. 

Pizzano and Suarez described a convenient preparation of a series of new chiral phosphine-phosphites based on the easy demethylation of o-anisyl phosphines [124]. Rh-156a complex was found to be the most effective catalyst for the hydrogenation of dimethyl itaconate (99.6% ee), whereas 155b and 156a induced >99% ee in the hydrogenation of methyl N-2-acetamidocinnamate. Reetz... 

Salzer et al. prepared a set of planar-chiral diphosphine ligands based on the arene chromium tricarbonyl backbone (Fig. 36.3) [21]. The straightforward four-step synthetic route allowed the preparation of 20 ligands of this family. These ligands were tested in Ru- and Rh-catalyzed enantioselective hydrogenation of various substrates, including the standard C=C substrates (dimethyl itaconate, methyl-2-acetamidocinnamate, methyl-2-acetamidoacrylate) as well as MEA-imine (l-(methoxymethyl)ethylidene-methylethylaniline) and ethyl pyruvate. Moderate conversions and ee-values were obtained. 

Itaconic acid (Eastman) and 2-acetamidoacrylic acid (Fluka) were CP grade a tropic acid was prepared according to the literature (53). Ruthenium and rhodium trichlorides were obtained as trihydrates from Johnson Matthey Limited. (+)Diop was obtained from Strem Chemicals a literature synthesis provided (-)diop (7). Racemic methyl phenyl sulfoxide was a K K product. 

A number of polymer latices falling into this category have been described in the literature bot they are still relatively novel and have not received the extensive attention given to the more conventional latices. Probably the systems of this type most extensively characterized are those described by Hoy (1979) and Bassett and Hoy (1980) which were prepared by copolymerizing methyl methacrylate, butyl acrylate, and ethji acrylate with an unsaturated add such as itaconic, aciyh c, or methylacrylic. The particles obtained appeared to consist of a spherical core particle sur-... 

The methyl methacrylate-itaconic acid copolymer, P(MMA-co-ItaA), was prepared by slow free-radical solution polymerization in methanol under nitrogen using 2,2 -azobis-(2,4-dimethyl valeronitrile)(du Pont Vazo 52) as initiator. The molar ratio of monomer to initiator was in the range of 5xl03 to 10xl03. Reaction at 50°C for 30 to 40 hrs gave conversions of 10 to 30%. The reaction mixture was added to cold, deionized water and the precipitated polymer obtained was rinsed with 2-propanol. 

In hydrogenations with H2 in D20 the product showed only CHD— stretches in the infrared. This observation excludes a fast H/D exchange on Pd, and implies a monohydridic mechanism of hydrogenation. With the same catalyst in an aqueous (D20) solution, itaconic acid is reduced under H2 to yield multiply deuterated methyl succinic acid having 1.97 deuterons at C3, 0.66 at C2 and none at Cl (Eq. 32) [83]. On the other hand, in an H20/ethyl acetate biphasic solvent mixture, the catalyst prepared in situ from [Rh(cod)Cl]2 and TPPTS catalyzed the reduction (with D2) of dimethyl itaconate with deuterium incorporation at C3 (2.06), C2 (0.78) and at Cl (0.18) [84], Similar results were obtained in toluene/methanol (1 1) with the Rh(I)-BPPM cationic catalyst [85], Again, these findings could be explained by a fast /3-elimination from the intermediate Rh(I)-alkyl. 

Stepwise substitution in the phenyl rings of phosphines such as BDPP creates new diastereomeric pairs due to chirality on phosphorus. In a detailed investigation into the hydrogenation of (Z)-a-acetamidocinnamic acid, its methyl ester and dimethyl itaconate, the catalyst was prepared from [Rh(cod)Cl]2 plus 2 equiv. of (2S,4S)-BDPP or its mono-, di-, tri-, or tetrasulfonated derivative (25-28) [93],... 

Four substrates were chosen for our study, methyl-2-acetamidoacrylate 2, methyl acetamidociimamate 3, dimethyl itaconate 4 and the Candoxatril precursor 5 (6) (Figure 1). The precatalysts [(/ ,/ )-Me-DuPHOS Rh (NBD)]BF4, (R.R)-7n, and [(5,5)-Et-DuPHOS Rh (NBD)]BF4, (.S, 5)-7b, were prepared according to literature... 

Methyl cinnamate (I) from Eastman Organic Chemicals was recrystallized from acetone-water solution and then sublimed. Dimethyl itaconate (V) was from Chas. Pfizer Company and purified by sublimation and preparative gas... 

In some cases, dicarboxylic acid monomers, which cannot be homopolymer-ized, like itaconic acid (lA) or fumaric acid, may be employed in a formulation. When incorporated into the latex particle, they offer the advantage of introducing two carboxyl groups per molecule of monomer (i.e., increasing the carboxyl loading) for enhanced colloidal stability or to increase the number of reactive sites available. For example. Lock et al. recently [23] studied the role which itaconic acid played in the nucleation of latex particles prepared via the emulsion copolymerization of n-butyl acrylate and methyl acrylate. 

The experimental data for the polymerization of itaconic acid in dioxane with initiators that are soluble in organic solvents are given Table VIII. The polymers prepared at 50 C were described as being slightly yellow in color and soluble in water, methanol, dioxane, dimethylformamide, dimethyl sulfoxide, formamide, and ethanol. Copolymers prepared at room temperature were colorless and had similar solubility behavior except that they were insoluble in cold dioxane but soluble in dioxane when heated to 70 "C. The polymers were insoluble in petroleum ether and in methyl ethyl ketone. 

Water is the ideal solvent from the cost and pollution viewpoints, but it is a non-solvent for many surface coating polymers. It will ssolve a small number of homopolymers, notably those derived from acrylamide, acrylic acid, itaconic acid, vinyl methyl ether, vinyl pyrrolidone and vinyl sulphonic acid, but none of these homopolymers forms flexible films of use in the coatings industry. While copolymers of acrylic or methacrylic acids with acrylate esters are generally insoluble in water, their salts are soluble when the acid content is over 5% (for hydrophilic monomers) and 12% (for hydrophobic monomers). Such polymers can be prepared in solution, or in emulsion, but not in aqueous solution. This is because the acrylate esters are insoluble in water. The acid is copolymerised in the un-ionised form because the ion is unreactive to free radicals. In emulsion polymerisation, care has to be taken to avoid homopolymerisation of the acrylic or methacrylic acid in the water phase. Suppression of homopolymerisation requires a low concentration of acid throughout the polymerisation process. This can be achieved by using a long reaction period and slow addition of monomer mixture, or by careful pH buffer selection. 

In 2001, Engel and Gade [57] prepared a series of chiral phosphine-functionalized poly(propyleneimine) (PPI) dendrimers (29) by the reaction of carboxyl-linked C2-chiral pyrphos ligand (pyrphos, 3,4-bis(diphenylphosphino) pyrrolidine) with commercially available zero- to fourth-generation PPI. The subsequent metallation of multisite phosphines with [Rh(COD)2]-BF4 (COD, 1,5-cyclooctadiene) was in situ generated and carried out in the asymmetric hydrogenation of Z-methyl-a-acetamido cinnamate and dimethyl itaconate (Figure 4.28, Equation 1). In contrast... 

Similar heterogeneous chiral catalysts were prepared by the impregnation of mesoporous Al-MCM-41, Al-MCM-48, and Al-SBA-15 with rhodium diphosphine organometaUic complexes and were tested for the hydrogenation of dimethyl itaconate, methyl a-acetamidoacrylate, and methyl a-acetamidocinnamate [90]. The immobilized catalysts showed high activity and excellent chemo- and enantioselec-tivities, that is, up to >99% conversion, 99% selectivity, and 98% ee. 

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