Structure of Simpler Organic Compounds. 125 



the type NH 2 R HC1. In this respect they differ from a 

 class of compounds which has already been mentioned, 

 namely, the acid amides. This class of substances has been 

 regarded (p. 101) as a derivative of ammonia, in which 

 a hydrogen has been substituted by an acidyl group (for 

 example, acetamide, CH 3 CO NH 2 ). The existence of this 

 group deprives the substance of its strongly basic character. 



The amines, which formed the subject of a series of 

 classical investigations by Hoffmann, to whose labours the 

 principal knowledge of these compounds is due, can be 

 prepared by the action of an alcoholic solution of ammonia 

 on alkyl iodides or bromides. A mixture of all three 

 compounds, together with another compound of the general 

 formula NR 4 I or NR 4 Br, known as a tetralkyl ammonium 

 iodide or bromide, is formed. 



The reactions involved may, in the case of ethyl iodide 

 and ammonia, be represented by the following equations : 



C 2 H 6 I + NH 3 C 2 H 3 NH 2 .HI 



2CJH.I + NH, = (C 2 H 5 ) 2 NHHI + HI 



3C 2 H 5 I + NH 3 = (C 2 H 6 ) 3 N.HI + 2HI 



(C 2 H 5 ) 3 N + C 2 H 6 I = N(G 2 H 6 )J 



In this reaction, a mixture of several products is obtained, 

 the separation of which is a matter of some difficulty. 

 There are, however, methods, which are described below, 

 for obtaining the primary amines pure and unmixed with 

 secondary or tertiary derivatives. If such a primary 

 amiiie is treated with the theoretical quantity of an alkyl 

 iodide and potassium hydroxide, it will yield the secondary 

 derivative 



(C 2 H 5 )NH 2 + C a H 5 I + KOH = KI + H 2 + (C 2 H 5 )NH (1) 



The secondary amine, in its turn, on heating with the same 

 reagents, will yield the tertiary compound 



(CAWNH + C,H 5 I + KOH - KI + H 2 + (C 2 H 5 ) 3 N (2) 



