Adipodinitrile

Aliphatic dinitriles, such as adipodinitrile, react with aliphatic diols at low temperature (0-5°C) in the presence of HC1 and form poly(iminoesters) which... 

At the cathode, olefins with electron deficient double bonds can be hydrodimer-ized (Eq. 1). This reaction has been developed for acrylonitrile [22] in a technical adipodinitrile synthesis [23] with a scale of more than 300.000 tons per year. The scope of this hydrodimerization has been substantiated with many examples [24-33]. 

Electroorganic synthesis deals with conversion of organic compounds into useful products by anodic oxidation or cathodic reduction. Today there exist literally thousands of published examples of electrosynthesis reactions but only a very small number—certainly not more than several tens—are really exploited commercially, the best known example being the cathodic hydrodimerization of acrylonitrile to adipodinitrile, a precursor to hexam-ethylene diamine, which is the aminoconstituent of nylon 6,6 (779) ... 

One could call this type of electrocatalysis, which is due to the catalytic action of adsorbed species, electrocatalysis of the second kind. Most remarkably the selectivity and commercial success of the Monsanto process— the hydrodimerisation of arylonitrile to adipodinitrile—... 

Cathodic hydrodimerization has been applied to a large number of electron-poor olefins. The most prominent example is the hydrodimerization of acrylonitrile to give adipodinitrile. This so-called Monsanto process has a production capacity of about 300,000 tons per year worldwide [20] ... 

DuPont has developed another commercial process, based on catalysis by a nitrilase (E.C. 3.5.5.1), to the solvent l,5-dimethyl-2-piperidone (1,5-DMPD) (Xolvone ) with applications in electronics and coatings (Thomas, 2002). The raw material is 2-methylglutaronitrile (MGN), a by-product during the manufacture of adipodinitrile (ADN) for nylon 6,6 discussed in the previous section. Such a raw material situation leads to coupling of nylon-6,6, 5-cyanovaleramide, and l,5-dimethyl-2-piperidone production, a situation that most likely is specific to DuPont and thus not prone to much competition. 

From the industry s point of view the most important electroorganic reaction is the cathodic hydrodimerization of acrylonitrile to adipodinitrile. The basic work and scaling up of the process were carried out by Monsanto. 

Adipodinitrile is an intermediate for hexamethylenediamine, the amine component of nylon 66. The electrochemical process is economically superior to the synthesis of adipodinitrile from cyclohexanone. Today, it essentially competes with the addition reaction of HCN to butadiene. The total capacity of the electrochemical ADN synthesis is currently about 250,000 tonnes/year. The process is industrially fully developed. Recent work 34 347) is aimed at reducing the oxygen evolution potential at the anode in order to save further energy. 

The new syntheses cannot compete with the established processes based on acetylene and formaldehyde, not least because the yields are still not very satisfactory. Adipodinitrile also can be obtained by reductive dehalogenation 433). 

Bartsch, M., Baumann, R., Haderlein, G., Flores M.A., Jungkamp, T., Luyken, H., Scheidel, J. and Siegel, W. (2005) Method for the production of adipodinitrile by hydrocyanation of 1,3-butadiene. PCT patent W020055073167 Al. BASF Aktiengesellschaft, Germany. 

Baizer-Monsanto process — (also called Monsanto process) is the reductive electrohydrodimerization of acrylonitrile, ACN, to adipodinitrile, ADN, an intermediate in the manufacture of Nylon 66 ... 

SYNS ADIPIC ACID DINITRILE ADIPIC ACID NITRILE ADIPODINITRILE 1,4-DICYANOBUTANE HEXANEDINTTRILE HEXANEDIOIC ACID DINITRILE NITRILE ADIPICO (ITALIAN) TETRAMETHYLENE CYANIDE... 

But even this is only a part of the whole story. In Ref 17 the BASF production site. Seal Sands, is discussed. All parts of the site are integrated in order to produce (HMDi) hexamethylenediamine. The ADN (adipodinitrile) process is only one part of the site (Fig. 1). 

The electrohydrodimerization of acrylonitrile was a milestone in the history of organic electrochemistry. The success of this process is associated with the name of Manuel M. Baizer. In 1960, he initiated the biggest success story of organic electrochemistry to date, namely, the Monsanto process for the hydrodimerization of ACN, acrylonitrile, to ADN, adipodinitrile (Scheme 3). 

Similar studies were carried out on the meso derivatives of the a, -dichloro- and dibromo-adipodinitriles (17) and (18) (see Scheme 21). These molecules have conformations similar to those of the corresponding esters and exhibit the same reactivity when exposed to ammonia, thus demonstrating for these systems a mechanism identical to that for the esters. 

Cramer studied the mechanism using Rh compounds [123, 124], The linear dimerization of acrylonitrile in the presence of hydrogen and a ruthenium catalyst to form 1,4-dicyano-l-butene [125-127] received much interest in industrial laboratories, mostly in Japan, so a large number of patents have been filed, in some of which palladium catalysts have also been claimed. The above compound can be hydrogenated to give the industrially important adipodinitrile and hexa-methylene diamine. 

Beilstein Handbook Reference) Adipic acid dinitrile Adipinsaeuredinitril Adipodinitrile Adiponitrile Adipyidinitrile AI3-11080 BRN 1740005 CCRIS 4570 1,4-Dicyanobutane EINECS... 

Glutarodinitrile,573 and also adipodinitrile, heptanedinitrile, and octanedinitrile,574 are converted into the a,a,aV-tetrachloro dinitriles when chlorine is passed into them at 70 to 75°, and hydrolysis of these products by boiling concentrated HC1 gives the corresponding tetrachloro dicarboxylic acids. 

Pentyl nitrate in dry tetrahydrofuran with potassium terf-butoxide as condensing agent has proved particularly valuable 160,161 for instance, by this method adipodinitrile at —50° gives 93% of the 2,5-dinitro derivative, which can be worked up to give 1,4-dinitrobutane by hydrolysis and decarboxylation.161... 

The preparation of adipodinitrile from adipic acid and ammonia is carried out industrially on a large scale in the gas phase by the fluidized-bed (BASF) and fixed-bed processes (ICI) (equation 1). Over the conventional catalysts, the selectivity is reduced by cyclization and simultaneous decarboxylation to form cyclopentanone, the reaction of that to yield cyclopentanoneimine and cyanocyclopetanoneimine (table 1). 

TABLE 1. Adipodinitrile from adipic acid and ammonia... 

These cyclization reactions are suppressed if a phosphorus-modified B-pentasil zeolite is used, as shown by comparison with the conventional silica-based catalyst. Only the silica carrier is replaced by a zeolitic carrier. The amount of cyclic compounds is reduced from 6.7 mol % to 1.4 mol %, and the yield of the desired product adipodinitrile is about 10 % higher [20]. This is evidently due to the restricted transition state shape selectivity of the pentasil zeolite the steric constrains of the zeolite framework prevent the formation of the transition state of the cyclic compounds. The reactions on the outer surface are responsible for the 1,4 mol-% yield of cyclic compounds. 

Adipic diamide. See Adipamide Adipic dihydrazide. See Adipic acid dihydrazide Adipic ketone. See Cyclopentanone Adipiodone. See lodipamide Adipodihydrazide. See Adipic acid dihydrazide Adipodinitrile. See Adiponitrile Adiponitrile... 

Synonyms Adipic acid dinitrile Adipic acid nitrile Adipodinitrile Adipyinitrile ADN 1,4-Dicyanobutane Hexanedinitrile Hexanedioic acid dinitrile Tetramethylene cyanide... 

In the synthesis of adipic acid one can start with benzene, phenol, tetrahydrofuran, butadiene, or cyclohexane. Benzene is converted to phenol (e.g., by the cumene process), this is hydrogenated to cyclohexanol, and the cyclohexanone gained by oxidation is then oxidized to adipic acid, HOOC—(CH2)4—COOH, with nitric acid. Cyclohexane can also be oxidized with air to cyclohexanol, from which adipic acid is obtained by direct nitric acid oxidation. Adipic acid can also be produced by saponification of adipodinitrile (adiponitrile), which in turn comes from tetrahydrofuran or butadiene (see below). 

Cydohexane is the most important cyclic alkane in industrial organic chemistry and plays a major role in the industrial production of important monomers, such as, for example, adipinic add, adipodinitrile, hexamethylenediamine, hexamethy-lene diisocyanate, and Eproduction processes cyclohexane is oxidized in the first step in a liquid-phase reaction to a mixture of cydohexanol and cyclohexanone. Details about this process are given in Sedion 5.3.3.1. 

Butadiene Polybutadiene, copolymers, chloroprene, adipodinitrile, sulfolene 9 (2009)... 

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