Adipic nitrile

Adiponitrile undergoes the typical nitrile reactions, eg, hydrolysis to adipamide and adipic acid and alcoholysis to substituted amides and esters. The most important industrial reaction is the catalytic hydrogenation to hexamethylenediarnine. A variety of catalysts are used for this reduction including cobalt—nickel (46), cobalt manganese (47), cobalt boride (48), copper cobalt (49), and iron oxide (50), and Raney nickel (51). An extensive review on the hydrogenation of nitriles has been recendy pubUshed (10). 

Analytical Procedures. Standard methods for analysis of food-grade adipic acid are described ia the Food Chemicals Codex (see Refs, ia Table 8). Classical methods are used for assay (titration), trace metals (As, heavy metals as Pb), and total ash. Water is determined by Kad-Fisher titration of a methanol solution of the acid. Determination of color ia methanol solution (APHA, Hazen equivalent, max. 10), as well as iron and other metals, are also described elsewhere (175). Other analyses frequendy are required for resia-grade acid. For example, hydrolyzable nitrogen (NH, amides, nitriles, etc) is determined by distillation of ammonia from an alkaline solution. Reducible nitrogen (nitrates and nitroorganics) may then be determined by adding DeVarda s alloy and continuing the distillation. Hydrocarbon oil contaminants may be determined by ir analysis of halocarbon extracts of alkaline solutions of the acid. 

Plasticizers. Monomeric (mol wt 250—450) plasticizers (qv) are predominantiy phthalate, adipate, sebacate, phosphate, or trimeUitate esters. Organic phthalate esters like dioctyl phthalate (DOP) are by far the most common plasticizers in flexible PVC. Phthalates are good general-purpose plasticizers which impart good physical and low temperature properties but lack permanence in hot or extractive service conditions and are therefore sometimes called migratory plasticizers. Polymeric plasticizers (mol wt up to 5000 or more) offer an improvement in nonmigratory permanence at a sacrifice in cost, low temperature properties, and processibiHty examples are ethylene vinyl acetate or nitrile polymers. 

Rubbers. Plasticizers have been used in mbber processing and formulations for many years (8), although phthaHc and adipic esters have found Htde use since cheaper alternatives, eg, heavy petroleum oils, coal tars, and other predominandy hydrocarbon products, are available for many types of mbber. Esters, eg, DOA, DOP, and DOS, can be used with latex mbber to produce large reductions in T. It has been noted (9) that the more polar elastomers such as nitrile mbber and chloroprene are insufficiendy compatible with hydrocarbons and requite a more specialized type of plasticizer, eg, a phthalate or adipate ester. Approximately 50% of nitrile mbber used in Western Europe is plasticized at 10—15 phr (a total of 5000—6000 t/yr), and 25% of chloroprene at ca 10 phr (ca 2000 t/yr) is plasticized. Usage in other elastomers is very low although may increase due to toxicological concerns over polynuclear aromatic compounds (9). 

The reasons why a tubular reactor was selected for the production of adipic acid nitrile from adipic acid and ammonia are discussed by Weikard (in Ullmann, Enzyldopaedie, 4th ed., vol. 3, Verlag Chemie, 1973, p. 381). 

A synthesis of great industrial interest is the electrochemical anodic reductive dimerisation of two molecules of acrylonitrile to give adiponitrile, from which adipic acid and 1,6-hexanediamine are prepared by hydrolysis and reduction, respectively, of the two nitrile groups. Polycondensation of the resulting products leads to Nylon 66 (Scheme 5.27). 

DSM jointly with Du Pont de Nemours308 have patented platinum catalysts generated from the water soluble sulfonated ligand 30 (Table 2 m=0, n=0, m=l, n=2 m=l, n=l, Ar=nBu-S03Li) and used in the aqueous phase hydroformylation of internally unsaturated carboxylic acids, esters or nitriles to their corresponding formyl derivatives which are useful intermediates for the preparation of di-carboxylic acids (e.g. adipic acid). For example, TOFs up to 105 h-1 were achieved in the hydroformylation of 3-pentenoic acid catalysed by Pt/30 (m=0, n=0) at 100°C and 80 bar CO/H2 to give aldehydes with a selectivity of 83% (n/i=3.4), valeric acid (4.6%) and adipic acid (8.1%).308 The products were separated from the aqueous catalyst solution by extraction with ether. Five recycles of the aqueous catalyst solution showed that the Pt/30 (m=0, n=0) catalyst retains its activity. 

Polyesters from propylene glycol and dicarboxylic acids, especially adipic and sebacic acid, are commercial products suggested for PVC as well as for cellulose esters. The well known Paraplex resins of Rohm Haas, which are compatible with nitrile and GRS rubber, belong to this group. Other products are the Ultramolls of Farbenfabriken Bayer. Some polyesters of this type have a tendency to exude on storage, especially if esterification is not complete. 

Adipimilrile undergoes the typical nitrile reactions, e.g.. hydrolysis to adipamide and adipic acid and alcoholysis to substituted amides and esters. 

Urinary and bile compounds Ethylene glycol adipate methyl silicone-nitrile phases... 

Depending on the gas and liquid residence times required, the reactor could be operated horizontally or vertically with either downflow or upflow. Weikard (in Ullmann, Enzyklopaedie, 4th ed., vol. 3, Verlag Chemie, 1973, p. 381) discusses possible reasons for operating an upflow concurrent flow tubular reactor for the production of adipic acid nitrile (from adipic acid and ammonia). The reactor has a liquid holdup of 20 to 30 percent and a residence time of 1.0 s for gas and 3 to 5 min for liquid. 

Sainsbury and co-workers (121) have synthesized several ellipticine dimers tethered through the C-5 methyl group (333) (Scheme 53) or the C-9 position (334). The 9-methoxy derivative of 333 was also prepared. The nitrile 329 was available from the Sainsbury ellipticine synthesis (122) and was transformed into the alkaloid 17-oxoellipticine (148). A clever maneuver was to add nitric acid to protonate the pyridine nitrogen of 330. This precluded A-oxide formation during dithiane hydrolysis. Reductive amination in two steps afforded the amine 332. Coupling with adipic acid gave the target bisellipticine 333. 

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

Biphasic hydrocyanations were described as early as 1976 using Ni/TPPTS catalysts [165, 244 d]. Adipic dinitrile and methylglutaronitrile are obtained from 3-pentene nitrile/butadiene (see Section 2.5). 

Synonyms Adipic acid dinitrile Adipic acid nitrile 1,4-Dicyanobutane Hexanedinitrile Tetra-methylene cyanide Chemical Formula C6HgN2... 

ADIPIC ACID DINITRILE or ADIPIC ACID NITRILE... 

The BASF process is recommended, e.g., for acrylic acid, adipic acid nitril, and /3-naphtol. According to Ritner and Steiner (1985), this process has not been used on a commercial scale. 

Ratio of the activity found in each product to the total activity of the products identified. The amines were purified to constant specific activity over a 4-m tricresyl phosphate column at 70 C, and a 4-m diisodecyl phthalate column at 80 C. The alcohols and the other oxygenated products were purified over a 10-m ft/3 oxydipropio-nitrile column at 80 C, and a 8-m diethyleneglycol adipate column at 100 C. Owing... 

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