Dinitriles dicarboxylic acid

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. 

Glutarlc acid (n =3), pimelic acid (n = 5) and suberic acid (n = 6) may be obtained from the corresponding dibromides. These are converted by aqueous - alcoholic potassium or sodium cyanide into the dinitriles, and tbs latter are smoothly hydrolysed by 60 per cent, sulphuric acid into the dicarboxylic acids ... 

They can also be prepared by the action of diiminoesters or dinitriles of dicarboxylic acids with hydrate ... 

The chemical transformation must not affect the stereogenic centers. Suitable acyclic candidates are compounds with easily convertible functional groups, such as diols, diamines, amino alcohols, dicarboxylic acids and so on. A number of procedures known before 1973 have been compiled, including conversion of diols and amino alcohols into sulfites or 1,3-dioxolanes by thionyl chloride, or acetalization with ketones31,1"319, as well as the conversions of dinitriles into imides320, dicarboxylic acids into cyclic anhydrides or imides321, and hydroxy acids into oxazolidones 322. 

There are several other convenient one- and two-step syntheses leading to enantiomerically pure bisoxazolines, e.g. condensation of amino alcohols with dicarboxylic acids, dinitriles,or diimino esters (cf. eq 2), or acid-catalyzed cyclization of (2-hydroxyalkyl)amides. By these methods, various types of differently substituted bisoxazoline ligands are readily available in both enantiomeric forms, often in high overall yield. 

Most dicarboxylic acids are prepared by adaptation of methods used to prepare monocarboxylic acids. Where hydrolysis of a nitrile yields a monocarboxylic acid, hydrolysis of a dinitrile or a cyanocarboxylic acid yields a dicarboxylic acid where oxidation of a methylbenzene yields a benzoic acid, oxidation of a di-methylbenzene yields a phthalic acid. For example ... 

Miscellaneous Routes. Polyamides have been prepared by other reactions, including addition of amines to activated double bonds, polymerization of isocyanates, reaction of formaldehyde with dinitriles, reaction of dicarboxylic acids with dllsocyanates, reaction of carbon suboxide with diamines, and reaction of diazlactones with diamines. These reactions are reviewed in Reference 4. 

Attempts to prepare cinnoline-3,4-dicarboxylic acid (94) from 3,4-dimethylcinnoline apparently foundered on the relative inertness of the 3-methyl group the hitherto unknown diacid was eventually formed by acid hydrolysis of the dinitrile (93), itself prepared as shown in Scheme 53. ... 

Treatment of quinoxaline-2,3-dicarboxylic acid anhydrides, diesters, or dinitriles with hydrazine monohydrate gives pyridazino[4,5-h]quin-oxalines (Scheme 7). ... 

Glutarodinitrile,573 and also adipodinitrile, heptanedinitrile, and octanedinitrile,574 are converted into the a,a,aV-tetrachloro dinitriles when chlorine is passed into them at 70 to 75°, and hydrolysis of these products by boiling concentrated HC1 gives the corresponding tetrachloro dicarboxylic acids. 

For conversion of aliphatic dinitriles into dicarboxylic acids it is best to use concentrated hydrochloric acid, e.g., for the preparation of glutaric acid from the dinitrile.622 Aromatic nitriles such as a-tolunitrile are hydrolysed by ca. 75% sulfuric acid. 

The dicarboxylic acid is converted to trimethyl hexamethylene diamine via the dinitrile. 

At first the unsubstituted metal-free quinoxalinoporphinazine 129 was obtained in a 67% yield by heating dinitrile quinoxaline-2,3-dicarboxylic acid in benzyl alcohol and chlorobenzene at 180°C with metallic lithium followed by the treatment of the resulting complex with dilute hydrochloric acid (1969ZOB2536).A higher yield of 129 (Ri = = R4 = H,... 

X = HH) (95%) is achieved when carried out in fusion with sodium hydroxide at 220 °C within 15 min (2006RUP2269530). Under the same condition the tert-butyl analogue 129 (R =R = R = H, R = f-Bu, X = HH) has been obtained from corresponding dinitrile quinoxaline-2,3-dicarboxylic acid 65j in a 75% yield (2008ZOB1214). Metal-free benzol ] quinoxalinoporphinazine 129 (R = R = H, R = R = Z1,... 

A systematic way of naming this class of compounds is as alkanenitriles. In common names, the ending -ic acid of the carboxylic acid is usually replaced with -nitrile. The chain is numbered like those of carboxylic acids. Similar rules apply to dinitriles daived from dicarboxylic acids. The substituent CN is called cyano. Cyanocycloalkanes are called cyclo-alkanecarbonitriles. We will retain the common name benzonitrile (from benzoic add), rather than use the systanatic benzenecarbonitrile. 

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