Naming nitriles

A cyanohydrin is an organic compound that contains both a cyanide and a hydroxy group on an aUphatic section of the molecule. Cyanohydrias are usually a-hydroxy nitriles which are the products of base-cataly2ed addition of hydrogen cyanide to the carbonyl group of aldehydes and ketones. The lUPAC name for cyanohydrias is based on the a-hydroxy nitrile name. Common names of cyanohydrias are derived from the aldehyde or ketoae from which they are formed (Table 1). 

Oleic acid, structure of, 1062 Oligonucleotide, 1114 synthesis of, 1114-1116 Olive oil, composition of, 1062 -otie. ketone name ending, 697 -otdtrile, nitrile name ending, 754 Optical activity, 294-296 measurement of, 295 Optical isomers. 297 Optically active, 295 Orbital. 4... 

Nitrile names are formed from common names of carboxylic acids. 

In substitutive lUPAC nomen clature cyanohydrins are named as hydroxy deriva tives of nitriles Because ni trile nomenclature will not be discussed until Section 20 1 we will refer to cyanohydrins as derivatives of the parent aldehyde or ketone as shown in the ex amples This conforms to the practice of most chemists... 

Substitutive lUPAC names for nitriles add the suffix nitrile fo fhe name of fhe parenf hydrocarbon chain fhaf includes fhe carbon of fhe cyano group Nifriles may also be named by replacing the ic acid or oic acid ending of the corresponding carboxylic acid with omtrile Alternatively they are sometimes given functional class lUPAC names as alkyl cyanides... 

Nitriles contain the —C=N functional group We have already discussed the two mam procedures by which they are prepared namely the nucleophilic substitution of alkyl halides by cyanide and the conversion of aldehydes and ketones to cyanohydrins Table 20 6 reviews aspects of these reactions Neither of the reactions m Table 20 6 is suitable for aryl nitriles (ArC=N) these compounds are readily prepared by a reaction to be dis cussed m Chapter 22... 

Nitriles are classified as carboxylic acid derivafives because fhey are convened fo car boxylic acids on hydrolysis The condifions required are similar fo fhose for fhe hydrol ysis of amides namely healing m aqueous acid or base for several hours Like fhe hydrolysis of amides nilrile hydrolysis is irreversible m fhe presence of acids or bases Acid hydrolysis yields ammonium ion and a carboxylic acid... 

Highly saturated nitrile elastomers (HSN) have become available. These mbbers are prepared by (nearly complete) hydrogenation of the nitrile mbber copolymer. The resulting product has better heat and oxidation resistance than conventional nitrile mbber but still retains some double bonds for vulcanization. Trade names for HSN are Zetpol (Nippon Zeon), Therbar (Bayer), and Tormac (Polysar). HSN has been used, and is being developed, for oil field chemical, automotive, power station, aerospace, military, and industrial appHcations (66). 

The trans-1,4 configuration predominates but there are also small amounts of the three other isomeric stmctures, ie, cis-1,4, -1,2, and -3,4. It was one of the first synthetic mbbers produced in the United States as early as 1931, by the Du Pont Co., because of its good solvent resistance. Its Du Pont trade name is neoprene. Even though it is not as solvent resistant as nitrile mbber, it has many other advantageous properties (see Elastomers,... 

The synthetic application of reactions based upon the intramolecular addition of a carbanion or its enamine equivalent to a carbonyl or nitrile group has been explored extensively. One class of such reactions, namely the Dieckman, has already been discussed in Section 3.03.2.2, since ring closure can often occur so as to form either the C(2)—C(3) or C(3)—C(4) bond of the heterocyclic ring. Some illustrative examples of the application of this type of ring closure are presented in Scheme 46. 

Acrylonitrile-butadiene rubber (also called nitrile or nitrile butadiene rubber) was commercially available in 1936 under the name Buna-N. It was obtained by emulsion polymerization of acrylonitrile and butadiene. During World War II, NBR was used to replace natural rubber. After World War II, NBR was still used due to its excellent properties, such as high oil and plasticizer resistance, excellent heat resistance, good adhesion to metallic substrates, and good compatibility with several compounding ingredients. 

Nitriles are classified as carboxylic acid derivatives because they are converted to carboxylic acids on hydrolysis. The conditions required are similar- to those for the hydrolysis of amides, namely, heating in aqueous acid or base for several hours. Like the hydrolysis of amides, nitrile hydrolysis is ineversible in the presence of acids or bases. Acid hydrolysis yields fflnmonium ion and a carboxylic acid. 

Nitrile rubber (NBR) was first commercialized by I.G. Farbindustry, Germany, in 1937, under the trade name of Buna N. Its excellent balance of properties confers it an important position in the elastomer series. Nitrile rubber, a copolymer of butadiene and acrylonitrile, is widely used as an oil-resistant rubber. The acrylonitrile content decides the ultimate properties of the elastomer. In spite of possessing a favorable combination of physical properties, there has been a continuous demand to improve the aging resistance of NBR due to the tougher requirements of industrial and automotive applications. 

Compounds containing the -C=N functional group are called nitriles and undergo some chemistry similar to that of carboxylic acids. Simple open-chain nitriles are named by adding -nitrile as a suffix to the alkane name, with the nitrile carbon numbered Cl. 

Nitriles can also be named as derivatives of carboxylic acids by replacing the -ic acid or -oic acid ending with -onitrile, or by replacing the -carboxylic acid ending Avith -carbonitriie. The nitrile carbon atom is attached to Cl but is not itself numbered. 

Derivatives of these acids formed by change in the carboxy group (salts, esters, lactones, acyl halides, amides, nitriles, etc.) are named according to 2-Carb-20.2. The anion takes the ending -uronate . Esters are also named using the ending -uronate . 

Pandey et al. have used ultrasonic velocity measurement to study compatibility of EPDM and acrylonitrile-butadiene rubber (NBR) blends at various blend ratios and in the presence of compa-tibilizers, namely chloro-sulfonated polyethylene (CSM) and chlorinated polyethylene (CM) [22]. They used an ultrasonic interferometer to measure sound velocity in solutions of the mbbers and then-blends. A plot of ultrasonic velocity versus composition of the blends is given in Eigure 11.1. Whereas the solution of the neat blends exhibits a wavy curve (with rise and fall), the curves for blends with compatibihzers (CSM and CM) are hnear. They resemble the curves for free energy change versus composition, where sinusoidal curves in the middle represent immiscibility and upper and lower curves stand for miscibihty. Similar curves are obtained for solutions containing 2 and 5 wt% of the blends. These results were confirmed by measurements with atomic force microscopy (AEM) and dynamic mechanical analysis as shown in Eigures 11.2 and 11.3. Substantial earher work on binary and ternary blends, particularly using EPDM and nitrile mbber, has been reported. 

C13-0051. Nitrile rubber, whose structure follows, is a copol Tner made Irom two monomers. The pol TTier is used to make automotive hoses and gaskets. Draw the stmctures of the monomers and name them. 

We also found that the occurrence of aldoxime dehydratase is as wide as that for nitrile-degrading enzymes such as nitrile hydratase, amidase and/or nitri-lase. All of the nitrile degraders hitherto isolated contained aldoxime dehydratase activities. The author would like to propose that the pathway in which aldoximes are successively degraded via nitrile could be named as the aldoxime-nitrile pathway (Fig. 1). 

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