Maleic anhydride derivatives

Isomerization. Maleic acid is isomerized to fumaric acid by thermal treatment and a variety of catalytic species. Isomerization occurs above the 130 to 140°C melting point range for maleic acid but below 230°C, at which point fumaric acid is dehydrated to maleic anhydride. Derivatives of maleic acid can also be isomerized. Kinetic data are available for both the uncatalyzed (73) and thiourea catalyzed (74) isomerizations of the cis to trans diacids. These data suggest that neither carbonium ion nor succinate intermediates are involved in the isomerization. Rather, conjugate addition imparts sufficient single bond character to afford rotation about the central C—C bond of the diacid (75). 

Reduction. Heterogeneous catalytic reduction processes provide effective routes for the production of maleic anhydride derivatives such as succinic anhydride [108-30-5] (26), succinates, y-butyrolactone [96-48-0] (27), tetrahydrofuran [109-99-9] (29), and 1,4-butanediol [110-63-4] (28). The technology for production of 1,4-butanediol from maleic anhydride has been reviewed (92,93). 

Lubrication oil additives represent another important market segment for maleic anhydride derivatives. The molecular stmctures of importance are adducts of polyalkenyl succinic anhydrides (see Lubrication and lubricants). These materials act as dispersants and corrosion inhibitors (see Dispersants Corrosion and corrosion control). One particularly important polyalkenyl succinic anhydride molecule in this market is polyisobutylene succinic anhydride (PIBSA) where the polyisobutylene group has a molecular weight of 900 to 1500. Other polyalkenes are also used. Polyalkenyl succinic anhydride is further derivatized with various amines to produce both dispersants and corrosion inhibitors. Another type of dispersant is a polyester produced from a polyalkenyl succinic anhydride and pentaerythritol [115-77-5]. 

L. H. Flett and W. H. Gardner, Maleic Anhydride Derivatives, John Wiley Sons, Inc., New York, 1952. 

The corresponding hydroxyazaquinones appear to exist mainly in their trioxo tautomeric forms. The only structure of this type, which has been described in subsequent trapping reactions (Scheme 8), is compound 4c (59JA6049). This compound when treated with o-phenylenediamine in acetic acid provided pyrido[2,3-6]quinoxaline 24. Reduction of 4c with zinc in acetic anhydride provided triacetoxypyridine derivative 25. Acidic hydrolysis of the azaquinone provided maleic anhydride derivative 27, probably via intermediate 26. 

See also Josephson entries Low temperature superconductors (LTS) Lube basestocks, dewaxing of, 16 844 Lube oil additives, maleic anhydride derivatives as, 15 512. See also Lubricant (lube) additives Lube oil sulfonates... 

The cyclization giving maleic anhydride derivative 163 is also characterized by low yield. Moreover, the total yield of the starting dicyanide 162 was about 25% based on 2-methylbenzothiophene (90BCJ1311). This inefficiency was typical of most of the syntheses of photochromic maleic anhydrides from nitriles. Hence, the development of more efficient methods is a very important problem. Anhydride 163 has been synthesized recently (08JACS7286) by the Perkin reaction in good yields in each step (Scheme 50). 

A simple method for the synthesis of maleic anhydride derivative 165 starting from 2,5-dimethyl-3-thienylboronic acid and commercially available inexpensive mucobromic acid 168 was reported (04IZV2238) (Scheme 52). The starting boronic acid was prepared in good yield from 2,5-dimethyl-3-iodothiophene. 

Structurally similar photochromic maleic anhydride derivatives 177 with a similar reaction mechanism were prepared by Irie (05CL64) by a one-pot synthesis from 2-methoxybenzothiophene, oxalyl chloride, and pentene-3-carboxylic acid (3-pentenoic acid) in dichloromethane in the presence of triethylamine at 5°C for 2 h according to Scheme 54. 

Maleic anhydride derivatives are readily making it possible to perform their transformations into photochromic N-alkyl-substituted dithienylma-leimides with primary amines. This method was used to prepare cyclic imides 187 in anhydrous methanol or ethanol at 20-80°C in 67-90% yields (02ZOR1390) and N-alkyl(aryl) derivatives 188 based on thieno[3,2-b]pyr-role (03IZV1719) in 70-90% yields. 

Regioselective reductions of the maleic anhydride derivatives (387) and (389) with lithium aluminum hydride yielded (388) and (390). Metallation of the O-methyltetronic acid (388) with lithium N- cyclohexyl-A- isopropylamide followed by treatment with, for example, p-anisaldehyde led to pulvinones such as (391) (79JCS(P1)70). 

Lubrication oil additives represent another important market segment for maleic anhydride derivatives Maleic anhydride is used in a multitude of applications in which a vinyl copolymer is produced hy the copolymerization of maleic anhydride with other molecules having a vinyl functionality. The use of maleic anhydride in llie manufacture of agricultural chemicals has declined ill the L ,S. since the early 1980s. 

G. B. Vermont, P. X. Riccobono and /. Blake The photosensitized reaction of dichloromaleic anhydride with benzene. A novel variation in the photochemistry of maleic anhydride derivatives. J. Amer. chem. Soc. 87, 4024 (1965). 

The sensitized photocycloaddition of maleic anhydride derivatives to thiophenes to give the exo adducts (76) has been known for... 

Flett, L. H., and Gardner, W. H., Maleic Anhydride Derivatives, New York, John Wiley and Sons, 1952. 

TABLE 10.10 The linear coefficient of thermal expansion-contraction for HDPE-based WPC. The published article [4] did not provide details on the formulation of the composite material. MAPP — maleic anhydride derivative of polypropylene (see Chapter 5). 

Various photochemical (2 + 2)-cycloadditions of heteroaromatic compounds have been reported in which an enone moiety is incorporated either into the olefinic reagent or into the heteroaromatic compound. Both furan and thiophene have been found to give cycloaddition reactions with maleic anhydride derivatives in the presence of a sensitizer.202 213 The cycloadducts (185 and 186) were formed in high yield, but in the case of 2,5-dimethylthiophene, cyclobutane formation was the minor pathway, as oxetane formation predominated.210 Cyclic enones, such as 2-cyclopenten-l-one and 2-cyclohexen-l-one reacted with furan to afford mixtures of (2 + 2)-cycloadducts (187a, R = H) and (188),... 

Other Elements - Further investigations of the benzophenone sensitised reactions of methyl-substituted selenophenes and tellurophenes with a range of maleic anhydride derivatives have been reported. Cleavage of the acyl-tellurium... 

A (2 + 2)-photoadduct is formed on irradiation of 2,3-dimethylmaleic anhydride with 3,4-dimethyl-1-phenylphosphole. " The photocycloaddition of maleic anhydride derivatives (124) to the alkene moiety in (125) affords the adducts (126) by a straightforward (2 + 2)-addition. The (2 + 2)-photoadducts (127) are readily produced by the dimerization of the corresponding maleic anhydrides in ethyl acetate solution.The intramolecular photochemical cyclization of the succinimide derivative (128) is a key step in the new synthetic approach to the tetracyclic fragment of neotuberostemonine. ... 

Miscellaneous Reactions. Trimethylsilyldiazomethane converts acid- and base-sensitive maleic anhydride derivatives into the corresponding bis(methyl esters) (eq 70). Terminal silyl enol ethers are conveniently prepared from aldehydes by first treating the carbonyl compound with TMSC(Li)N2, followed sequentially by methanol and Rh2(OAc)4 (eq 71). The method works well with base-sensitive substrates and is superior to the attempted regioselective deprotonation/O-silylation of the corresponding methyl ketone. ... 

A new route to pleiadienes involves photoaddition of maleic anhydride derivatives to acenaphthene, oxidative removal of the anhydride groups, and ring-opening of the resulting cyclobutenes (Scheme 18). Schmidt has reported further details of the synthesis of optically active tricarbonyl(cyclobutadiene)iron complexes, the first step involving [2 + 2] addition of 1,2-dichloroethylene to dichloromaleic anhydride. 

Enzymatic syntheses within the microfluidic platform were also reported. The construction and novel compound synthesis from a synthetic metabolic pathway consisting of a type HI polyketide synthase (PKS) known as 1,3,6,8-tetrahydroxynaphthalene synthase (THNS) from Streptomyces coelicolor and soybean peroxidase (SBP) in a microreactor were performed (Fig. 5) [11]. THNS immobilized to Ni-NTA agarose beads was prepacked into a microfluidic channel, while SBP was covalently attached to the walls of a second microfluidic channel precoated with a reactive poly(maleic anhydride) derivative. The result was a tandem, two-step hiochip that enabled synthesis of novel polyketide derivatives. The first microchan-nel, consisting of THNS, resulted in the conversion of malonyl-CoA to flaviolin in yields of up to 40% with a residence time of 6 min. This conversion is similar to that obtained in several-milliliter batch reactions after 2 h. Linking this microchannel to the SBP microchannel results in biflaviolin synthesis. During the course of this work, we discovered that the substrate specificity of THNS could be manipulated by simply changing the reaction pH. As a result, the starter acyl-CoA specificity can be broadened to yield a series of truncated pyrone products. When combined with variations in the ratio of acyl-CoA and... 

The mechanism is shown in Scheme 10 and involves reductive elimination of bromide anions to give quinodimethane intermediates (19) that polymerize. In the case of o-quinodimethane, their intermediacy has been proved by trapping via Diels-Alder reaction with a reactive maleic anhydride derivative [63, 64]. The second elimination step is analogous to the cathodic eliinination of vicinal dihalides, which is known to give tra s-alkenes [65]. 

L.H. Flett, W.H. Gardner, "Maleic Anhydride Derivatives", John Wiley, New York, 1952, p. 191. 

Thus, there are several maleic anhydride derivatives that can be obtained through radical-initiated reaction. Alkyl radicals are shown to react with MA much faster than methylmaleic anhydride.The initiation may be obtained with peroxide, AIBN, or, in some cases, light. It would be difficult to assess the importance of MA s radical reaction without including the homo and copolymerization aspects, which are included elsewhere in the book. Suffice it to say that these two aspects may contribute to formation of undesired by-products and could potentially be prevented or curtailed significantly. 

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