CHEMICAL PKOPERTIES OF FATTY ACIUS AND KELATED COMPOUNDS 137 



^0 ^0 



RC-CI + HNH2 *RC-NH2+HCI 



Acid Amide 



chloride 



The preparation of amides directl}^ from the neutral fats can be carried 

 out by ammonolysis. Under such conditions, ammonia or a substituted 

 amine acts as the hydrolysis agent. 



RC-OR +HNH2 ^RC-NH2+R OH 



Ester Amide 



Oda^^^ observed a quantitative transformation of fats into fatty acid 

 amides when they were heated in a sealed tube with ammonia at 150°C. 

 for one hour. Anilides are formed by heating aniline and fats in a sealed 

 tube at 230°C. for 5 hours. ^<"' Amides may likewise be synthesized by 

 treatment of aliphatic esters with aqueous solutions of aliphatic amines 

 under pressure at above 100°C., preferably^"^ 200°C. 



The nitriles have also been shown to be a possible source of the amides. 

 This synthesis is effected by treatment with concentrated hydrochloric 

 acid, sulfuric acid, or glacial acetic acid at low temperatures. This reac- 

 tion simpl}^ involves the addition of one molecule of water as follows: 



RCiN + HzO — — ^RC-NHz 

 Nitrile Amide 



Oxidation with H2O2 in alkaline solution will convert the nitriles to amides, 

 \\\\X\ the simultaneous liberation of oxygen.^"^ 



b'. Properties of Acid Amides: The amides of the fatty acids are com- 

 pounds with relatively high melting points. They do not show the grada- 

 tion in physical properties, with changes in chain length, that are usually 

 the rule with homologous series. The melting points are an example of this 

 lack of conformity. Alternation does not occur, the melting points are 

 quite irregular, and show little variation for the higher members of the 

 series. Thus, there is a difference of only 3.8° in the melting point of 

 caprylamide and stearamide. On the other hand, the anilides show a 

 somewhat greater regularity in melting point, reaching a minimum in those 

 having 8 and 9 carbon atoms, after which there is a uniform rise with the 

 lengthening of the chain. •^'^^ However, the A^-methyl amides have been 



«' R. Oda, &ci. Papers Inst. Phys. Chem. Research Tokyo, 24, No. 510, 171-173 (1934). 

 ^"«E. de'Coiiiio and R. Biazzo, Rend, accad. sci. Napoli, [3], 21, 322-327 (1915); 

 ./. Chem. Soc, 110, 788 (1916). 



501 C. O. Henke and W. H. Zartman, U. S. Patent No. 2,058,013 (Oct. 20, 1936). 



*»2 B. Radziszewski, Ber., 18, 355-356 (1885). 



503 p. W. Robertson, /. Chem. Soc, 93, 1033-1037 (1908); 115, 1210-1223 (1919). 



