Dicarboxylic from dinitriles

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 ... 

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. ... 

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. 

When some heterocyclic dicarboxylic anhydrides are heated in contact with a glowing nichrome wire, the dinitrile is formed [167] probably via a heteryne, for example, o-phthalonitrile was obtained in 72% yield from quinoxaline-2,3-dicarboxylic anhydride. 

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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