CHAPTER V 



NITRO AND AZO DYES 



1. NITROSO DYES (QUINONE OXIMES) 



The nitroso dyes are produced by the action of nitrous acid on 

 phenoHc compounds, according to the equation 



OH OH 



J+HNO. = f |+H,0 



NO 



{nitrosophenol) 



The fact, however, that the quinone oxime produced by the 

 action of hydroxylamine on p-quinone according to the equation 



O O 



l + NH.OH = f l+H.O 



O NOH 



(quinoneoxime) 



is identical with the nitrosophenol produced as shown above, 

 shows that in all probability the substances can react as quinone- 

 oximes, which better accounts for their behavior as dyeing agents 

 since the quinone ring 



or 



Y ^' 



occurs frequently in other dyes as a chromophore (see page 30). 



as naphthol green y c. I. NO. 1* 



Synonyms: Fast printing green. Gamhine. 



NOH 



v—O 



C10H7NO2; Mol. Wt. 173.164 

 {An acid dye) 



*This abbreviation stands for the number in the "Colour Index;" see Chapter 

 III, p. 36. 



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