Nouveaux dérivés du stilbène, leur préparation et leurs applications, notamment comme agents d'éclaircissement ou azurants optiques

摘要

1,051,294. Dichlorostilbylnaphthtriazole sulphonic acids. J. R. GEIGY A.G. July 8, 1965 [July 9, 1964], No. 29038/65. Heading C2C. [Also in Divisions C5 and D1] Novel optical brighteners of the formula are made by coupling the diazonium compound of 4-amimo-21,41- or 31,41-dichlorostilbene-2-sulphonic acid with an unsulphonated 2-aminonaphthalene or one sulphonated in the 1-position and oxidizing the o-amino dyestuff, wherein of X 1 and X 2 , one X is hydrogen and the other is chlorine. In the examples the oxidation is effected by using a catalyst comprising copper sulphate and monoethanolamine together with, as oxidant, air.