Maleic production

Process Technology Evolution, Growth in the worldwide maleic anhydride industry is exclusively in the buianc-lo-inaleic anhydride route, often at the expense of benzene-based production. Table 2 shows I 995 and estimated 1996. 1997. and 2000 worldwide maleic production capacity broken down in categories of benzene, butane and phlhalie anhydride coproduct. As can be seen from this table butane routes are expected to grow at the expense of benzene-based processes. 

CHa CHlCH CHO. Colourless lachrymatory liquid with a pungent odour. B.p. 104 "C. Manufactured by the thermal dehydration of aldol. May be oxidized to crotonic acid and reduced to crolonyl alcohol and 1-butanol oxidized by oxygen in the presence of VjOj to maleic anhydride. It is an intermediate in the production of l-butanol from ethanol. 

Used as fibres, particularly in textiles and film. Many other polyester polymers are of importance, e.g. unsaturated polyester resins from phthalic anhydride, propylene glycol and maleic anhydride used with reinforcement in boats, cars, etc. (alkyd resins). U.S. production 1983 1-7 megatonnes. 

Anthracene and maleic anhydride. In a 50 ml. round-bottomed flask fitted with a reflux condenser, place 2 0 g. of pure anthracene, I 1 g. of maleic anhydride (Section 111,93) and 25 ml. of dry xylene. Boil the mixture under reflux for 20 minutes with frequent shaking during the first 10 minutes. Allow to cool somewhat, add 0 5 g. of decolourising carbon and boil for a further 5 minutes. Filter the hot solution through a small, preheated Buchner funnel. Collect the solid which separates upon coohng by suction filtration, and dry it in a vacuum desiccator containing paraffin wax shavings (to absorb traces of xylene). The yield of adduct (colourless crystals), m.p. 262-263° (decomp.), is 2-2 g. Place the product (9 10-dihydroanthracene-9 10-cndo-ap-succinic anhydride) in a weU-stoppered tube, since exposure to air tends to cause hydration of the anhydride portion of the molecule. 

Another class of reaction where you can see at once that the disconnection is the reverse of the reaction is Pericychc Reactions. An example would be the Diels-Alder reaction between butadiene and maleic anhydride. Draw the mechanism and the product. 

Carbonyiation of butadiene gives two different products depending on the catalytic species. When PdCl is used in ethanol, ethyl 3-pentenoate (91) is obtained[87,88]. Further carbonyiation of 3-pentenoate catalyzed by cobalt carbonyl affords adipate 92[89], 3-Pentenoate is also obtained in the presence of acid. On the other hand, with catalysis by Pd(OAc)2 and Ph3P, methyl 3,8-nonadienoate (93) is obtained by dimerization-carbonylation[90,91]. The presence of chloride ion firmly attached to Pd makes the difference. The reaction is slow, and higher catalytic activity was observed by using Pd(OAc) , (/-Pr) ,P, and maleic anhydride[92]. Carbonyiation of isoprcne with either PdCi or Pd(OAc)2 and Ph,P gives only the 4-methyl-3-pentenoate 94[93]. 

Donor substituents on the vinyl group further enhance reactivity towards electrophilic dienophiles. Equations 8.6 and 8.7 illustrate the use of such functionalized vinylpyrroles in indole synthesis[2,3]. In both of these examples, the use of acetyleneic dienophiles leads to fully aromatic products. Evidently this must occur as the result of oxidation by atmospheric oxygen. With vinylpyrrole 8.6A, adducts were also isolated from dienophiles such as methyl acrylate, dimethyl maleate, dimethyl fumarate, acrolein, acrylonitrile, maleic anhydride, W-methylmaleimide and naphthoquinone. These tetrahydroindole adducts could be aromatized with DDQ, although the overall yields were modest[3]. 

Nucleophilic addition of 2-aminothiazole to the double bond of di-maleic acid hydrazine has been reported (206). No spectroscopic proof, however, is given to establish the proposed structure (60) for the resulting product (Scheme 41). 

The product of a Diels-Alder cycloaddition always contains one more ring than was present m the reactants The dienophile maleic anhydride contains one ring so the product of Its addition to a diene contains two... 

The radical-catalyzed polymerization of furan and maleic anhydride has been reported to yield a 1 1 furan-maleic anhydride copolymer (89,91). The stmcture of the equimolar product, as shown by nmr analyses, is that of an unsaturated alternating copolymer (18) arising through homopolymerization of the intermediate excited donor—acceptor complex (91,92). 

The oxidative reaction of furan with bromine in methanol solution or an electrochemical process using sodium bromide produces 2,5-dimethoxy-2,5-dihydrofuran (19), which is a cycHc acetal of maleic dialdehyde. The double bond in (19) can be easily hydrogenated to produce the corresponding succindialdehyde derivative. Both products find appHcation in photography and as embalming materials, as well as other uses. 

Washing and cleaning agents containing salts of maleic acid—furan copolymers (106) form complexes with alkaline-earth ions. These cleaning compositions do not contain phosphoms or nitrogen and find use in metal, foodstuff, and machine dishwashing products. 

Uses. Union Carbide consumes its vinyl ether production in the manufacture of glutaraldehyde [111-30-8J. BASF and GAF consume most of their production as monomers (see Vinyl polymers). In addition to the homopolymers, the copolymer of methyl vinyl ether with maleic anhydride is of particular interest. 

MixedPhosphona.te Esters. Unsaturated, mixed phosphonate esters have been prepared from monoesters of 1,4-cyclohexanedimethanol and unsaturated dicarboxyhc acids. Eor example, maleic anhydride reacts with this diol to form the maleate, which is treated with benzenephosphonic acid to yield an unsaturated product. These esters have been used as flame-retardant additives for thermoplastic and thermosetting resias (97). 

Ethyl and butyl esters of poly(vinyl methyl ether)/maleic anhydride (PVM/MA) copolymer were introduced in the early 1960s for use in hair sprays. These polymers also have free carboxy acid groups that can be neutralized. Recommended neutralization is 10%, but products can be found in the range of 5—30%, and recommended neutralizers include ammonium hydroxide, aminomethyl propanol, and triisopropano1 amine. These were the most widely used polymers in hair sprays before their use decreased dramatically in the early 1990s. 

Growth in the use of acetylene for the production of 1,4-butanediol is projected to continue at the rate of about 5% per year. However, competition from a new technology based on maleic anhydride may impact the use of acetylene in this market. 

Reactions of /l-Butane. The most important industrial reactions of / -butane are vapor-phase oxidation to form maleic anhydride (qv), thermal cracking to produce ethylene (qv), Hquid-phase oxidation to produce acetic acid (qv) and oxygenated by-products, and isomerization to form isobutane. 

Production of maleic anhydride by oxidation of / -butane represents one of butane s largest markets. Butane and LPG are also used as feedstocks for ethylene production by thermal cracking. A relatively new use for butane of growing importance is isomerization to isobutane, followed by dehydrogenation to isobutylene for use in MTBE synthesis. Smaller chemical uses include production of acetic acid and by-products. Methyl ethyl ketone (MEK) is the principal by-product, though small amounts of formic, propionic, and butyric acid are also produced. / -Butane is also used as a solvent in Hquid—Hquid extraction of heavy oils in a deasphalting process. 

Reactions. Mahc acid undergoes many of the characteristic reactions of dibasic acids, monohydric alcohols, and a-hydroxycarboxyUc acids. When heated to 170—180°C, it decomposes to fumaric acid and maleic anhydride which sublimes on further heating (see Maleic anhydride, maleic acid, AND FUMARIC acid). MaUc acid forms two types of condensation products linear malomalic acids and the cycHc dilactone or maUde it does not form an anhydride. 

The initial step of production is carried out in a titanium reactor (34) because of the high corrosivity of maleic acid to most metals under the drastic reaction conditions used. The other steps are performed in stainless steel equipment. Improved purification processes for malic acid have been patented (37,38). 

Maleic anhydride and the two diacid isomers were first prepared in the 1830s (1) but commercial manufacture did not begin until a century later. In 1933 the National Aniline and Chemical Co., Inc., installed a process for maleic anhydride based on benzene oxidation using a vanadium oxide catalyst (2). Maleic acid was available commercially ia 1928 and fumaric acid production began in 1932 by acid-catalyzed isomerization of maleic acid. 

V- Alkylpyrroles react with maleic anhydride to give the electrophilic substitution product (7) and not the Diels-Alder addition product found for... 

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