Ryan, Ai.gar, and O'Connicll — Syntheses of Some New Dyes. 93 



nitrite. This tetrazotised solution was added to a cold solution of 30 grams 

 of sodium carbonate, the mixture being stirred vigorously during the addition. 

 A solution of 12 grams of resorcin, in a little water, was added immediately, 

 and the stirring continued for about 8 hours, when the mixture was allowed 

 to stand overnight. It was then heated to 80° C, and the colouring matter 

 precipitated by the addition of common salt, when it was filtered and dried. 

 It was repeatedly purified from dilute alcohol. 



•2374 substance gave 15-6 c.cs. moist nitrogen at 16° C. and 765 mm. P., 



corresponding to N = 7'80, 

 C 24 H, 4 12 N 4 lSra 2 S 3 requires N = 8-10. 



The pure compound is a dark-bluish amorphous powder, dissolving in 

 water to a light cherry-red solution, and dyes cotton directly a beautiful 

 maroon shade. 



11. Coupling of Benzidine-Sulphone-Disulphonic Acid with Hydroqainone. 



OH S0 3 Xa S0 3 Na OH 



I l_ _l I 



/\_w_ N _/ \ / \_ N - N -/\ 



v x so 2 / y 



OH OH 



The benzidine-sulphone-disulphonic acid (22*3 grams) was dissolved in 

 150 c.cs. of water, and tetrazotised in the usual manner with 7 - 2 grams of 

 sodium nitrite. The tetrazotised solution was added to a cold solution of 

 30 grams of sodium carbonate, the mixture being stirred mechanically, and 

 12 grams of hydroquinone, dissolved in a small quantity of water, was added 

 immediately. After stirring the mixture vigorously for eight hours, it was 

 left standing overnight. It was then heated on a water-bath to 80° C, and, 

 having been maintained at this temperature for half an hour, common salt 

 was added when the precipitated colouring matter was filtered and dried. 

 The dye-stuff' is a brown sandy-coloured amorphous powder giving a light 

 amber-coloured solution in water. It was purified by separation on cooling 

 from hot dilute alcohol, and acted on cotton as a direct dye giving a buff 

 shade. 



•1S50 substance gave 12-3 c.cs. moist nitrogen at 15° C. and 768 mm. P., 



corresponding to N = 7*96, 

 C 21 H u 12 S 3 lS T a 2 iSr 4 requires N = 8-10. 



R.I.A. PROC, VOL. XXXIV, SECT. B. [j\] 



