Dicarboxylic acid ester anhydrides

Polycondensation of diols with dicarboxylic acids is often performed in the melt. However, it does not always lead to high-molecular-weight polyesters. Sometimes, the starting materials or the resulting polyester are thermally unstable at the high condensation temperatures. If the reactants and the polyester are well soluble, one can carry out the polycondensation in solution (see Example 4-2). The elimination of water from diols and dicarboxylic acids frequently occurs rather slowly. In such cases suitable functional derivatives of the diols and dicarboxylic acids (esters or anhydrides) can be used instead of the direct condensation, as described in Sect. 4.1.1.3. 

Procedures have been reported to convert 67 into the corresponding imide (74) (73USP3736299), dicarboxylic acid (75), anhydride (76), and a variety of acid/esters (77) and diesters (78) (75USP3915974). Chromic acid oxidation of 2,3-dichloroquinoxaline has also been reported as a route to 75 (58RTC842). 

Lithium diisopropylamide N,N,N, N -tetramethylethylenediamine Maleic acid anhydrides from Y,6-ethylene-a-dicarboxylic acid esters via 1,2-carbonyl migration... 

Via intermediates v.i. Cleavage of ethers via silicates OR OH s. 11, 24 Dicarboxylic acids from dicarboxylic acid esters GOOR -> GOOH via dicarboxylic acid anhydrides—Sterically hindered compounds s. 14, 28 ... 

Dicarboxylic acid anhydrides from dicarboxylic acid esters... 

Mixed esters containing the dicarboxylate moiety, eg, cellulose acetate phthalate, are usually prepared from the partially hydroly2ed lower aUphatic acid ester of cellulose in acetic acid solvent by using the corresponding dicarboxyhc acid anhydride and a basic catalyst such as sodium acetate (41,42). Cellulose acetate succinate and cellulose acetate butyrate succinate are manufactured by similar methods as described in reference 43. 

Since 3-methylenecyclobutane-l,2-dicarboxylic anhydride is easily converted to 3-methyl-2-cydobutene-l,2-dicarboxylic acid, it is an intermediate to a variety of cyclobutenes. The dimethyl ester of 3-methylenecyclobutane-l,2-dicarboxylic acid is also a versatile compound on pyrolysis it gives the substituted allene, methyl butadienoate, and on treatment with amines it gives a cyclobutene, dimethyl 3-methyl-2-cyclobutene-l,2-di-carboxylate. ... 

The scope of this reaction is similar to that of 10-21. Though anhydrides are somewhat less reactive than acyl halides, they are often used to prepare carboxylic esters. Acids, Lewis acids, and bases are often used as catalysts—most often, pyridine. Catalysis by pyridine is of the nucleophilic type (see 10-9). 4-(A,A-Dimethylamino)pyridine is a better catalyst than pyridine and can be used in cases where pyridine fails. " Nonbasic catalysts are cobalt(II) chloride " and TaCls—Si02. " Formic anhydride is not a stable compound but esters of formic acid can be prepared by treating alcohols " or phenols " with acetic-formic anhydride. Cyclic anhydrides give monoesterified dicarboxylic acids, for example,... 

So far, various dicarboxylic acid derivatives, dicarboxylic acids, their activated and non-activated esters, cyclic acid anhydrides, and polyanhydrides have been polymerized with glycols through lipase catalysis to give polyesters. 

Various combinations of dicarboxylic acid derivatives and glycols enzymatically afforded polyesters under mild reaction conditions. Dicarboxylic acids as well as derivatives, activated and non-activated esters, cyclic acid anhydride, and polyanhydrides, were found to be useful as monomer for the enzymatic synthesis of polyesters. 

The formation of relatively ill-defined catalysts for epoxide/C02 copolymerization catalysts, arising from the treatment of ZnO with acid anhydrides or monoesters of dicarboxylic acids, has been described in a patent disclosure.968 Employing the perfluoroalkyl ester acid (342) renders the catalyst soluble in supercritical C02.969 At 110°C and 2,000 psi this catalyst mixture performs similarly to the zinc bisphenolates, producing a 96 4 ratio of polycarbonate polyether linkages, with a turnover of 440 g polymer/g [Zn] and a broad polydispersity (Mw/Mn>4). Related aluminum complexes have also been studied and (343) was found to be particularly active. However, selectivity is poor, with a ratio of 1 3.6 polycarbonate polyether.970... 

Hydroxycarbonylation and alkoxycarbonylation of alkenes catalyzed by metal catalyst have been studied for the synthesis of acids, esters, and related derivatives. Palladium systems in particular have been popular and their use in hydroxycarbonylation and alkoxycarbonylation reactions has been reviewed.625,626 The catalysts were mainly designed for the carbonylation of alkenes in the presence of alcohols in order to prepare carboxylic esters, but they also work well for synthesizing carboxylic acids or anhydrides.137 627 They have also been used as catalysts in many other carbonyl-based processes that are of interest to industry. The hydroxycarbonylation of butadiene, the dicarboxylation of alkenes, the carbonylation of alkenes, the carbonylation of benzyl- and aryl-halide compounds, and oxidative carbonylations have been reviewed.6 8 The Pd-catalyzed hydroxycarbonylation of alkenes has attracted considerable interest in recent years as a way of obtaining carboxylic acids. In general, in acidic media, palladium salts in the presence of mono- or bidentate phosphines afford a mixture of linear and branched acids (see Scheme 9). 

The ultraviolet absorption spectra of compounds II from D-glucose and XI from D-fructose show an absorption band at 250 m/j, in accordance with their furan character.9 The product of periodate oxidation (V) and the dimethyl ester of the derived dicarboxylic acid (III) absorb at 285 and 262 m/i, respectively. The anhydrides of the condensates, XXXIV, do not exhibit selective absorption in the ultraviolet region, but the product of their oxidation (XXXVI) with periodic acid shows8 a band at about 270 m/i. 

A racemic alcohol may be converted into a racemic acid by reaction with one molar equivalent of phthalic anhydride the product is a half ester of a dicarboxylic acid (see Section 7.9.1). This can now be subjected to the resolution process for acids and, in due course, the alcohols can be regenerated by hydrolysis of the ester. 

Cyclohexanedicarboxylic acid, diethyl ester, CIS-, 29 Cyclohexanone, 90 4-Cyclohexene-I, 2-dicarboxylic ACID, diethyl ester, CIS-, 29 4-Cyclohexene-1,2-dicarboxylic anhydride, CIS-, 93... 

Pyrrole- and indole-carboxylic acid chlorides react with dialkyl- and diaryl-cadmium to yield the ketones and it is noteworthy that the reaction of the anhydride of indole-2,3-dicarboxylic acid with diphenylcadmium produces 3-benzoylindole-2-carboxylic acid and not its isomer (53JCS1889). The ability of l-methylindole-2-carboxylic acid to react with nucleophiles is enhanced by conversion into the mixed anhydride with methanesulfonic acid. The mixed anhydride reacts with carbanions derived from diethyl malonate and from methyl acetate to yield the indolyl (3- keto esters (80TL1957). 

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