192 Certain New Derivatives in the Aromatic Series. 



When resorcine was utilized, dyes were made of the formulie, 

 C^H-.N = ?^.CsH3(0H), and CgH^Br^.N = N.CgH3(0H), , 

 or written to show graphic constitution, 



Br OH 



Br/ >— N = N— r ^ 



i .OH 



\ / 



Br 



\/ 



Another proof was furnished by these two dyes that the bromine 

 was a detriment to clear colors, for the dye with the bromine in its 

 make-up was thrown towards the orange hue again. 



Another derivative which would show the difference between 

 dyes holding bromine and those with no bromine in the constitu- 

 tion was the color made when diazotized aniline or tri-brom-aniline 

 respectively, were treated with Seville and Winther's acid, alpha- 

 naphtol-mono-sulphonic acid, 1 : 4. The bromine-holding dye gave 

 the constitutional formula, 



Br OH 



Br< >— N = N— /' 



-/ 



/ 



Br \ / 



S03Na 



The commercial name of the dye without bromine is Tropaolin. 



Dyes with the hydroxyl in the beta position were made with and 

 also without bromine. These are the analogue of Crocein Orange 

 or Ponceau 4GB. The formula of the bromated compound is, 



CeH.Brg.N = N.C,„H5. -^ go^Na(6) ' 



Further details do not seem to be requisite. The comparison 

 of the two dyes, when purified and dyed on wool, show that the 

 bromine flattens the shade. 



The isomeric beta-Naphtol-di-sulphonic acids, "R" and " G", 

 were the next naphtol sulphonic acids which were utilized with the 

 wish of giving another proof of the possibilities of bromine in the 



