摘要 |
Compounds of the general formula <FORM:1055184/C2/1> wherein R1 and R2 each represent a hydrogen atom, an alkyl radical, an alkoxy radical, an aryl radical or a halogen atom, or R1 and R2 together represent the residue of a condensed benzene ring, are prepared by (a) reacting an o-amino-phenol or an o-amino-naphtholwit h an acid chloride of a 2-, 3- or 4-cyancinnamic acid to yield an N-acyl intermediate which is subsequently heated in the presence of an inert gas to 150 DEG to 300 DEG C., or (b) heating the o-amino-phenol or o-amino-naphthol with the acid chloride in the presence of an acid catalyst in an inert organic solvent.ALSO:Compounds of the general forumla: <FORM:1055184/D1-D2/1> wherein R1 and R2 each represent a hydrogen atom, an alkyl radical, an alkoxy radical, an aryl radical or a halogen atom, or R1 and R2 together represent a condensed benzene nucleaus, are employed in the form of solutions in water or in organic solvents or as dispersions to brighten fibrous materials. Chemical bleaching agents may be used together with said optical brighteners. Specified fibrous materials are the polyesters of the polyethylene glycol terephthalate type, polyamides and acetylated cellulose. |