140 II. CHEMISTRY OF FATTY ACIDS AND GLYCEROL 



drolysis apparently occurs by a direct substitution of a hydroxyl radical for 

 the amino group. 



c'. Reactions of Acid Amides : When the amides are heated alone or in 

 the presence of such dehydrating agents as phosphorus pentoxide or phos- 

 phorus pentachloride, they lose one molecule of water, and are converted to 

 the nitriles. 



RC-NHa^ =-RClN 



Amide Nitrile 



When the amides are subjected to hydrogenation they are converted to a 

 mixture of primary and secondary amines which have largely lost their 

 lipid-like properties. Thus, after reduction of such amides as lauramide in 

 dioxane under 100-300 atmospheres of hydrogen pressure, at 175-200 °C., 

 in the presence of copper-chromium oxide as a catalyst, Adkins and Woj- 

 cik^^^ obtained 40-70% of the primary amines and 25-50% of the secondary 

 amines. 



When the amides are treated with halogens in a strong alkaline solution, a 

 substituted urea is formed which eventually gives rise to the corresponding 

 amine. This reaction, first described by Hofmann,^^^ presumably involves 

 the intermediate formation of an isocyanate. The mechanism of this re- 

 arrangement has been studied extensively by Stieglitz and his associ- 

 ates. ^^^~^^'' These workers believe that only nitrogen compounds which can 

 lose constituents and form a monovalent nitrogen atom are capable of such a 

 rearrangement. 



(/) Nitriles. The nitriles are less closely related to the fatty acids than 

 are the amides, since they no longer contain any oxygen atoms. They 

 are highly reactive compounds by virtue of the unsaturated nitrogen atom. 

 They may readily be converted to acid amides, fatty acids, amines, and a 

 number of related compounds. They have the general formula, RCiN. 



a'. Methods of Preparation of Nitriles: As has been described earlier 

 the nitriles can be formed from the amides which, in turn, originate from 

 the fatty acids. Wohler and Liebig^^* were the first to describe this syn- 

 thesis, as early as 1832. Phosphorus pentoxide is the dehydrating agent 

 most frequently employed, but phosphorus pentasulfide has been success- 

 fully used in a number of instances. ^^^ 



"3 H. Adkins and B. Wojcik, J. Am. Chem. Soc, 56, 247 (1934). 



5" A. W. Hofmann, Ber., IJ,, 2725-2736 (1881). 



"5 F. Lengfeld and J. Stieglitz, Am. Chem. J., 15, 215-222, 504-518 (1893); 16, 370- 

 372 (1894). 



5i« J. Stieglitz, Am. Chem. J., 18, 751-761 (1896); 29, 49-68 (1903); Rev. Am. 

 Chem. Research, 9. 169-170 (1903), in /. Am. Chem. Soc. 25 (1903). 



"7 J. Stieglitz and R. B. Earle, Am. Chem. J., 30, 399-412, 412-421 (1903). 



518 F. Wohler and J. Liebig, Ann., 3, 249-282 (1832). 



619 T.. TTenry, Ber., 2, 305-308, 494-495 (1869). 



