Dimethyl adipate, synthesis

One process that capitalizes on butadiene, synthesis gas, and methanol as raw materials is BASF s two-step hydrocarbonylation route to adipic acid(3-7). The butadiene in the C4 cut from an olefin plant steam cracker is transformed by a two-stage carbonylation with carbon monoxide and methanol into adipic acid dimethyl ester. Hydrolysis converts the diester into adipic acid. BASF is now engineering a 130 million pound per year commercial plant based on this technology(8,9). Technology drawbacks include a requirement for severe pressure (>4500 psig) in the first cobalt catalyzed carbonylation step and dimethyl adipate separation from branched diester isomers formed in the second carbonylation step. 

While all previous examples employ enzymatic ROP, there are two reports on block copolymer synthesis employing enzymatic poly condensation. The first one was published by Sharma et al. and describes the synthesis and solid-state properties of polyesteramides with poly(dimethylsiloxane) (PDMS) blocks [21]. The polycondensation was carried out with various ratios of dimethyl adipate. 

Carboxylation of dienes and trienes, which takes place in a stepwise fashion, affords mono- or dicarboxylated products.146 Cobalt carbonyl,147 palladium chloride,148 149 and palladium complexes150 were used. 1,4 Addition to 1,3-butadiene gives the corresponding unsaturated tram ester (methyl trans-3-pentenoate) in the presence of [Co(CO)4]2 and a pyridine base.147 The second carboxylation step requires higher temperature than the first one to yield dimethyl adipate. In a direct synthesis (110°C, 500 atm, then 200°C, 530 atm) 51% selectivity was achieved.147... 

Similar to the synthesis of the difunctional polysulfone macroinitiator, a polyester was used in the synthesis of block copolymers by ATRP. The a, co-dihydroxy terminal polymer was synthesized by the transesterification of 1,6-hexanediol with dimethyl adipate [237]. The end groups were then esterified with 2-bromo-propionyl bromide and the ATRP of styrene yielded the ABA triblock copolymers. 

Hilker et al (44) combined dynamic kinetic resolution with enzymatic polycondensation reactions to synthesize chiral polyesters from dimethyl adipate and racemic secondary diols. The concept offered an efficient route for the one-pot synthesis of chiral polymers from racemic monomers. Palmans at al (18,43) generalized the approach to Iterative Tandem Catalysis (ITC), in which chain growth during polymerization was effected by two or more intrinsically different catalytic processes that were compatible and complementary. 

In this work we have shown that it is possible to use an ezyme to catalyze the polycondensatioh reaction to form polyamides. The large number of polyamides that have been made indicate diat lipases from Candida antarctica and Mucor miehei are rather nonspecific and can be used generally for polyamide synthesis. In a particular example, a water-soluble polyamide has been produced from dimethyl adipate and ethylene triamine via this enzyme-catalyzed reaction at 50-110°C. The enzymatic polymerization is easy to do and... 

FIGURE 8.6 Synthesis of segmented poly(ester amidejs derived from bisamide-diols, dimethyl adipate, and 1,4-butanediol based on Ref. [35]. 

For the synthesis of an optically active polyester from a racemic monomer, a new method of dynamic kinetic resolution was used. A mixture of stereoisomers of a secondary diol, a,a -dimethyl-l,4-benzenedimethanol, were enzymatically polymerised with dimethyl adipate (Scheme 12.6, [1]) [32]. 

For this reaction, the early investigations of Reppe pointed out the need for catalyst precursors to operate at high pressure [2], It is necessary to work at 150-300 bar of CO in order to stabilize the two catalytic species [Co(H)(CO)4] or [Ni(H)(X)(CO)2] that adopt a mechanism analogous to the cobalt-catalyzed hydroformylation [44,45]. Many industrial applications have been reported [28,46,47] for the synthesis of plasticizers and detergents. Similarly, the two-step methoxycarbonylation of 1,3-butadiene has been explored by BASF and other companies to produce dimethyl 1,6-hexanedioate (adipate) directly from the C4 cut [28,48]. The first step operates at 130 °C and... 

A similar synthesis of mechanistic interest rather than preparative value involves the thermal reaction of dimethyl 2,5-bisdiazo-3,4-diketoadipate (89, Scheme 23) with benzofuran (91)." The presumed intermediate is the pyrone cation 90 produced from the adipate 89 by the Wolff rearrangement, cyclization, and loss of nitrogen. Electrophilic substitution then affords the benzofuran 92, which can be isolated. Ring opening and cyclization of the resultant ketene 93 then affords the dibenzofuran 94 in poor (0.4%) yield. 

Process Economics Program Report SRI International. Menlo Park, CA, Isocyanates IE, Propylene Oxide 2E, Vinyl Chloride 5D, Terephthalic Acid and Dimethyl Terephthalate 9E, Phenol 22C, Xylene Separation 25C, BTX, Aromatics 30A, o-Xylene 34 A, m-Xylene 25 A, p-Xylene 93-3-4, Ethylbenzene/Styrene 33C, Phthalic Anhydride 34B, Glycerine and Intermediates 58, Aniline and Derivatives 76C, Bisphenol A and Phosgene 81, C1 Chlorinated Hydrocarbons 126, Chlorinated Solvent 48, Chlorofluorocarbon Alternatives 201, Reforming for BTX 129, Aromatics Processes 182 A, Propylene Oxide Derivatives 198, Acetaldehyde 24 A2, 91-1-3, Acetic Acid 37 B, Acetylene 16A, Adipic Acid 3 B, Ammonia 44 A, Caprolactam 7 C, Carbon Disulfide 171 A, Cumene 92-3-4, 22 B, 219, MDA 1 D, Ethanol 53 A, 85-2-4, Ethylene Dichloride/Vinyl Chloride 5 C, Formaldehyde 23 A, Hexamethylenediamine (HMDA) 31 B, Hydrogen Cyanide 76-3-4, Maleic Anhydride 46 C, Methane (Natural Gas) 191, Synthesis Gas 146, 148, 191 A, Methanol 148, 43 B, 93-2-2, Methyl Methacrylate 11 D, Nylon 6-41 B, Nylon 6,6-54 B, Ethylene/Propylene 29 A, Urea 56 A, Vinyl Acetate 15 A. 

Asahi Chemical is said to have been using the Kolbe synthesis for the production of sebacic acid for 20 years now. The electrolysis itself is one of three chemical steps (Scheme 7). In the first step, the monoester of adipic acid is produced. This is anodically dimerized to dimethyl sebacate. This ester is hydrolyzed to give crude sebacic acid. 

Various other processes not discussed here lead to mamrfacture of acids required for production of plasticizers. As previously mentioned, availability and price of acid rrray predetermine price and thus the likelihood of a plasticizer s itse. Acids are used not orrly in their pure forms but also in form of rrrixtures. For example DBE intermediates manrrfac-tured by DuPont are refined dimethyl esters of adipic, glutaric, and succinic acid are rrrix-tures for plasticizer synthesis.There are six mixtures of different composition which may be used for the production of polyester and diester plasticizers. Diester plasticizers are produced by transesterification according to the following equation ... 

Katayama S, Murakami T (1976), Synthesis of alternating polyantide esters by melt and solution polycondensation of N,N -di(6-hydroxycaproyl)diamines and N-6-hydroxycaproyl aminoalcohol with terephthahc and adipic dimethyl esters and dichlorides , J. Appl. Pol. Sci., 20 (4), 975—994. 

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