3-[[2-(acetyloxy)ethyl][4-[(4-nitrophenyl)azo]phenyl]amino]propiononitrile

Orange powder. Insoluble in water.

Disperse orange 31 is an orange-orange dye commonly used for fiber dyeing.

Non flammable

The synthetic azo dye Disperse Orange 31 was wrongly substituted by Disperse Orange 3 in patch test materials from Chemotechnique. This situation explains why a relatively low percentage of patients positive to PPD were positive to Disperse Orange 3, although a coreaction is explained to be very frequent because of skin transformation of Disperse Orange 3 into PPD.

250ml flask into 50g of water, turn on the stirring, into the p-nitroaniline 10g, into the 30% industrial hydrochloric acid 25kg, pulping for 2 hours, add ice cooling to 0 , directly 5g of sodium formulated into 30% sodium solution into the flask, the temperature does not exceed 5 , and then at 0-5 heat preservation and stirring for 1 hour filtration to be used. In 1000ml beaker add 50g of water, sulfuric acid 5g, and N-cyanoethyl-N-acetoxyhydroxyethyl aniline 13g, urea 0.3g, ping ping 0.1g, add ice cold to about 2 , and the above diazoxide solution coupled with the coupling temperature control at 0-5 , 3 hours, at about 5 dropwise addition of 11g of liquid alkali, add the end of the mixing for 1 hour after filtration, washing to neutral, that is, the structure product of dispersion orange 31. The structure product dispersed orange 31.

[1] Koh J. Dyeing with disperse dyes[J]. Textile dyeing, 2011, 10: 195-220.