5-Cyanovaleramid

Ammonolysis is the preferred route currently in use at the DuPont Company for the depolymerization of nylon-6,6 carpet waste. McKinney13 has described the reaction of nylon-6,6 and nylon-6 mixtures with ammonia at temperatures in the range of 300-350°C at a pressure of about 68 atm in the presence of an ammonium phosphate catalyst to form a mixture of nylon-6,6 and nylon-6 monomers (HMD A, A A, and s-caprolactam) and adiponitrile, 5-cyanovaleramide, 6-aminocapronitrile, and 6-aminocaproamide. 

The packed-bed reactor configuration commonly employed with immobilized enzymes yields a higher degree of conversion or higher space-time yield than a CSTR, the typical configuration for soluble enzymes. Examples are the nitrile hydratase-catalyzed process to 5-cyanovaleramide (5-CVAM) (Chapter 7, Section 7.1.1.3) or the decarboxylation of D,L-aspartate to D-aspartate, L-alanine, and C02 (Section 7.2.2.5). 

In basic chemicals, nitrile hydratase and nitrilases have been most successful. Acrylamide from acrylonitrile is now a 30 000 tpy process. In a product tree starting from the addition of HCN to butadiene, nicotinamide (from 3-cyanopyridine, for animal feed), 5-cyanovaleramide (from adiponitrile, for herbicide precursor), and 4-cyanopentanoic acid (from 2-methylglutaronitrile, for l,5-dimethyl-2-piperidone solvent) have been developed. Both the enantioselective addition of HCN to aldehydes with oxynitrilase and the dihydroxylation of substituted benzenes with toluene (or naphthalene) dioxygenase, which are far superior to chemical routes, open up pathways to amino and hydroxy acids, amino alcohols, and diamines in the first case and alkaloids, prostaglandins, and carbohydrate derivatives in the second case. 

Nitrile Hydratase Acrylamide from Acrylonitrile, Nicotinamide from 3-Cyanopyridine, and 5-Cyanovaleramide from Adiponitrile... 

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. 

S. M. Cooper, J. E. Gavagan, B. Stieglitz, S. M. Hennessey, and R. DiCosimo, 5-Cyanovaleramide production using immobilized Pseudomonas chlororaphis B23, Bioorgan. Med. Chem. 1999, 7, 2239-2245. 

Similarly, DuPont employs a nitrile hydratase (as whole cells of P. chlororaphis B23) to convert adiponitrile to 5-cyanovaleramide, a herbicide intermediate [122]. In the Lonza nitrotinamide (vitamin B6) process [123] the final step (Fig. 1.42) involves the nitrile hydratase (whole cells of Rh. rhodocrous) catalysed hydration of 3-cyanopyridine. Here again the very high product purity is a major advantage as conventional chemical hydrolysis affords a product contaminated with nicotinic acid, which requires expensive purification to meet the specifications of this vitamin. 

Hann, E.C., Eisenberg, A., Eager, S.K., et al. 1999.5-Cyanovaleramide production using immobilized Pseudomonas chlororaphis B23. Bioorganic and Medicinal Chemistry, 7 2239-45. 

Cyanovaleramide is used as intermediate for the synthesis of the DuPont herbicide azafenidine (Fig. 19-39). The whole cells from Pseudomonas chlororaphis are immobilized in calcium alginate beads. The biotransformation itself is catalyzed by a nitrile hydratase that converts a nitrile into the corresponding amide by addition of water. Nitrile hydratases belonging to the enzyme class of lyases (E.C. 4) are not be... 

The Comamonas Nil activities were determinated on AdN and four putative intermediates 5-cyanovaleramide, CVA, adipamate and adipamide (Table 3). 

Cyanovaleramide (prepn. s. 160) hydrogenated with Raney-Ni at 80°/100 atm. in dioxane... 

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