406 Prof. Raphael Meldola on the 



The analogy between the /3-naphthol and /3-naphthylamine 

 azo-derivatives leads naturally to a corresponding formula for 

 the latter : — 



N.NH.0 6 H 5 ...(«) XN.NH.C 6 H 5 ...(«) 



O 10 il 6v I or OioJtieW 



X NH (£) NNH (0) 



Both this formula of Zincke's and that of the author indi- 

 cate a relationship of the /3-naphthylamine azo-derivatives to 

 the azimido-compounds of Griess, as was first pointed out by 

 the author in 1884 *. These compounds would in fact be, 

 according to this point of view, hydrazimides ; and in apparent 

 confirmation of this Zincke f made the important discovery 

 that these and other orthoamidoazo-compounds lost two atoms 

 of hydrogen under the influence of oxidizing agents and gave 

 rise to colourless products resembling the azimido-compounds 

 in appearance and properties. 



This account may be taken as a brief exposition of the views 

 which have been, or are still held with respect to the consti- 

 tution of these /3-azo-compounds. In accordance with the 

 suggested forniulse, these derivatives no longer contain 

 hydroxyl or amidogen, and this is considered to account for 

 the differences in character which have already been pointed 

 out. According to the old view, the compounds in question 

 would be formulated in the same manner as their a- ana- 

 logues : — 



1 TT / V/ ft TI / V/ 



x OH (/3) Nra 2 (/3) 



Although responsible in common with Liebermann for one 

 of the first attempts to replace these older formulse by sym- 

 bolical expressions which appeared more in harmony with the 

 then known properties of the compounds in question, it must 

 be admitted that the experimental evidence acquired in more 

 recent times does not bear out the view that amidogen and 

 hydroxyl are absent. In the first place Nietzki and Goll { 

 found that, by means of the diazo-reaction, amidoazo-jS-naph- 

 thalene could be converted into the corresponding /3-naphthol 

 compound, i. e., 



N 2 .C 10 H 7 ,N 2 .C 10 H 7 



C 10 H/ into Cio-rL 



10 6x NH 2 (73) 6x OH(/3) 



* Journ. Chem. Soc, Trans. 1884, p. 116. 

 t Ber. 1885, pp. 3134 & 3142. 

 \ Ber. 1886, p. 1281. 



