Halides 1,1-dinitriles

Farona and Kraus have postulated the existence of both a- and rr-bonded dinitrile complexes of manganese carbonyl halides and suggest that the monomeric jr-complexes are the kinetically favoured species, whereas the CT-bonded complexes are thermodynamically favoured. ... 

The cyclization reactions of a,oj-dinitriles under the influence of anhydrous hydrogen halides (Eq. 3) at 0-25° have proved to be of considerable synthetic value. A range of aromatic heterocyclic systems becomes available, since it is possible for the exo-imine double... 

A few early references ascribe cyclic structures to the action of hydrogen halides on a, j-dinitriles. Soderback89 assigned structure... 

TABLE X. Pyridines Prepared by Hydrogen Halide Cyclization of 1,3-Dinitriles... 

Polyesters have been synthesized by the reaction of glycols with the diammonium or bis(triethylammonium) salts or fV-methylpyrrolidone complexes of dibasic acids. Dicarboxamides or dinitriles also react with glycols to form polyesters. Alkylene halides and salts of terephthalic acid react to give polyesters. In general, however, all these reactions give low-molecular-weight products, and no kinetic studies have been made. 

Cyclization of a,o)-dinitriles under acidic conditions has been reviewed thoroughly by Johnson and Madronero. Anhydrous hydrogen halides are favored for such reactions and a wide range of five-, six-and seven-numbered heterocyclic systems are produced. 

Ammonia and amines react with partially or fully activated carboxylic acid derivatives (acylating reagents) like acid anhydrides, acid halides, ammonium salts of monoesters, monoamides with heating, diesters under basic conditions and dinitriles after partial hydrolysis. ... 

Dinitriles such as (83.6) react with hydrogen halides (review [2547]) to give pyrimidine imino-halides. 

Ring closure with the formation of a carbon-nitrogen bond, of the types A-E shown in Fig. 1, has been used to synthesize derivatives of 1-, 2-, and 3-benzazepines, with aminocarboxylic acids, amino halides, dihalides, dinitriles, dicarboxylic acids, and carboxylic acid diamides as starting materials. The yields were generally fair to good. In some cases preferential formation of a five- or six-membered ring was observed. 

The commercial diamines used for nylon manufacture are usually best made by hydrogenation of the corresponding dinitriles. Hexamethylene-diamine is made by hydrogenation of the adiponitrile. Adiponitrile is now commercially produced by several methods. In the oldest method, ammonium adipate was catalytically dehydrated to the dinitrile. In a method developed since World War II, butadiene is treated with chlorine to produce mixture of dichlorobutenes. Reaction with hydrogen cyanide in the prewnce of cuprous halides yields l,4-dicyanobutene-2 exclusively. Hy-dn enation produces adiponitrile. 

Dicyanopropenes provide a valuable source for ring-closure reactions and have been used in a variety of syntheses of N-heterocycles. When a,j -unsaturated esters 424 reacted with 10, pyridones 425 were obtained and were in turn converted into dinitrile 426 with cyanamide. 426 was cyclized by hydrogen halides and yielded products 427 and 428 (X = Cl, Br, I). Dehalogenation afforded 429 and 430 Ionic species like 431 or... 

Cyclization of o,cu-dinitriles in the presence of anhydrous hydrogen halides affords cyclic imidoyl chlorides. For example, addition of hydrogen bromide to succinonitrile causes an immediate precipitation of the imidoyl bromide XL, ... 

A variety of similar dinitriles react with hydrogen bromide to afford cyclic halides... 

Improved cyclohydrations could be performed with cyclic acetals in place of the previously used imino derivatives of 0x0 compounds such as oximes or semicarbazones A facile ring closure of suitably o-subst. benzonitriles to anthracene rings has been published. Gyclization of dinitriles with hydrogen halides affords an efficient isoquinoline ring synthesis... 

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