OF AROMATIC COMPOUNDS. 63 



there likewise resulted at the anode a blue dye, which 

 showed a behavior analogous to that of the dye 

 obtained from p-phenylene-diamine. 



5. Electrolytic Reduction of Nitro-Compounds. 



In general, azo-, hydrazo-, and amido-compounds 

 result from the electrolytic reduction of nitro-com- 

 pounds. In this way Kendall 1 obtained aniline from 

 nitre-benzene, and Elbs a and Haussermann * prepared 

 the normal reduction products of nitfo-phenol. The 

 formation of azoxy-, azo-, amido-, or hydrazo-com- 

 pounds was dependent upon whether acid or alkaline 

 solutions were employed. If nitro-benzene is reduced 

 in a concentrated acetic or formic acid solution, to 

 which a few drops of concentrated sulphuric acid 

 (to increase the conductivity) have been added, the 

 corresponding salts of benzidene result; a fact further 

 confirmed by Lob. 4 



According to the investigations of the same author, 

 in the electrolysis of an ammoniacal solution azo- 

 benzene is formed as the chief product and hydrazo- 

 benzene as a secondary product. 



Gattermann and Koppert * obtained p-amido-phenol- 



1 German Pat., 21131. 



2 Journ. prakt. Chem., 49, 39. 

 1 Chem. Zeitung, 17, 129, 209. 



4 Ztschr. f. Elektrochem., 3, 471. 



5 Chem. Zeitung, 17, 210. 



