| 摘要 |
4,41 - Di -(benzoxazolyl - 2) - stilbene derivatives of the of the formula <FORM:1062257/C2/1> wherein each X is the same and represents a halogen atom or an alkyl or aryl radical and each n is the same and is 0, 1, or 2, are prepared by heating (1) a 4,41-stilbene-dicarboxylic acid or a C1- 4 dialkyl ester thereof with an ortho-hydroxyphenylamine or an ortho-alkoxyphenylamine in which the alkoxy group has 1 or 2 carbon atoms in the presence of pyrophosphoric acid, a polyphosphoric acid, metaphosphoric acid or phosphoric anhydride; or (2) a symmetrical acylamide of the formula <FORM:1062257/C2/2> wherein R represents hydrogen, ethyl or methyl, in the presence of the above-specified phosphorus compounds. The symmetrical acylamides of the above general formula are prepared by heating a 4,41-stilbene dicarboxylic acid dihalide of the formula <FORM:1062257/C2/3> wherein Z represents chlorine or bromine, with an ortho-hydroxyphenylamine or an ortho-alkoxyphenylamine in which the alkoxy group has 1 or 2 carbon atoms in an inert solvent.ALSO:Polyethylene, polypropylene and polyethylene terephthalate fibres and cloth are brightened by treatment, with aqueous dispersions of 4, 4-di-(benzoxazolyl-2)-stilbene derivatives of the formula:- <FORM:1062257/D1-D2/1> wherein each X is the same and represents a halogen atom or an alkyl or aryl radical and each n is the same and is O, 1 or 2. |
