Cyanogen chloride amides

Cupric chloride, see Carbon tetrachloride Cyanazine amide, see Cvanazine Cyanoethylene, see Acrylonitrile Cyanogen chloride, see Aniline, Benzene. 

Schiff bases (14), which are formed by reaction between DAMN and appropriate carbonyl reagents, are oxidatively cyclized to give a variety of 2-substituted 4,5-dicyanoimidazoles (15) (Scheme 2.1.5). Although dichlorodicyanoquinone (DDQ) or diaminosuccinonitrilc (DISN) have been used frequently to achieve the oxidative cyclization, long reaction times (17 h to 4 days under reflux) are a disadvantage, and N-chlorosuccinimide (NCS) under basic conditions is more convenient in many cases. The Schiff bases are best formed from aromatic aldehydes, but aliphatic aldehydes and ketones, ketoesters, orthoesters, amides, imidates and cyanogen chloride have all been used [15, 41-49J. 

Cyanamide.—An important compound formed from cyanogen chloride is known as cyan-amide and as its name indicates is composed of the cyanogen radical linked to the amine radical. It may be formed by the action of ammonia, in ethereal solution, on cyanogen chloride. 

Acylation with phosgene occurs under very mild conditions to give enamino-acyl chlorides which undergo solvolysis to esters or amides (Scheme 93). Cyanogen chloride reacts with enamines to give cyanoenamines and a-cyanoketones on hydrolysis. Cyanogen bromide and iodide react differently a 1 1 adduct is formed which, on hydrolysis, leads to 2-haloketone (Scheme 94). 

The preparation of alkyl, alkenyl, and aryl derivatives of cyanoacetylene (1) poses no particular problems. In most cases a terminal acetylene is metalated or converted into an alkynyl Grignard reagent, and these intermediates are subsequently intercepted by a cyano source , which in most cases is either cyanogen chloride or bromide and sometimes cuprous cyanide or phenyl cyanate. Of course, dehydration of an acetylenic amide as described for the parent molecules is also possible and has occasionally been employed. 

Further examples of the Ritter reaction(cf. section IV.B) are provided by the many substituted olefins that may be protonated to ve carbonium ions which can be intercepted by hydrogen cyanide or organic nitriles cyanogen chloride can also be used as intercepting species , but offers no advantages. Mixtures of the two possible amides, and hence amines, are to be expected from non-terminal alkenes and from such olefinic compounds as oleic acid Olefins may also be converted to amines with yields of up to 60%, by hydroboration and subsequent reaction of the organoborane with chloroamine in alkaline solution or preferably with hydroxylamine-0-sulphonic acid in diglyme (reaction 86) The reaction is applicable... 

In this series, too, replacement of the N-methyl by a group such as cyclopropylmethyl leads to a compound with reduced abuse potential by virtue of mixed agonist-antagonist action. To accomplish this, reduction of 24 followed by reaction with tertiary butylmagnesium chloride gives the tertiary carbinol 27. The N-methyl group is then removed by the classic von Braun procedure. Thus, reaction with cyanogen bromide leads to the N-cyano derivative (28) hydrolysis affords the secondary amine 29. (One of the more efficient demethylation procedures, such as reaction with ethyl chloroformate would presumably be used today.) Acylation with cyclopropylcarbonyl chloride then leads to the amide 30. Reduction with lithium aluminum hydride (31) followed by demethylation of the phenolic ether affords buprenorphine (32).9... 

Allyl alcohols readily react with trichloroacetonitrile to give the corresponding trichloroacetimidates 145. Activation of the double bond with electrophilic reagents results in ring closure to yield oxazolines 146. The most commonly employed electrophiles include iodine, iodine monochloride, phenylselenyl chloride, and mercuric trifluoroacetate. Other nitriles including cyanogen bromide and N,N-dimethylcyanamide can also be used. Since oxazolines readily hydrolyze to amides, the net effect of this reaction sequence is to produce p-amino alcohols 147 from an allyl alcohol. This strategy has been employed in numerous total syntheses of natural products. Examples are listed in Table 8.18 (Fig. 8.7 Scheme 8.43). ° ... 

Diaminophenylarsinic acid reacts with acyl chlorides in the usual manner, but its interaction with chloraeetamide has led to a discussion as to whether one or both of the amino-groups react with the amide. By the interaction of cyanogen bromide and 3 4-dianunophenylarsinic acid the following type of compound is produced ... 

Tertiary amines have to be dealkylated first, before the amide can be made. Dealkylation is normally carried out with cyanogen bromide or a chloroformate such as vinyloxycarbonyl chloride (Fig. 7.8). 

Figure 14-1 Functionalization and activation of electrode materials, a) silanization of supports bearing hydroxylic groups b) reaction with cyanuric chloride c) activation with cyanogen bromide d) binding via amide bonds after activation with 1,1-carbonyldiimidazole e) activation with good leaving groups such as tresyl chloride f) formation of Schiff bases between aldehyde groups on the support and amino groups at the biomolecule g) activation of carboxylic groups with carbodiimides or h) via the acid chlorides.

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