| 摘要 |
A process for the preparation of 4,4'-bis[benz(ox, othi or imid)azol-2-yl]stilbenes of the formula <IMAGE> in which R, R1, R2 and R3 are identical or different and denote hydrogen, C1-C4-alkyl, C1-C4-alkoxy, C1-C4-alkoxycarbonyl, chlorine, bromine, nitro or sulfo and X denotes oxygen, sulfur or NH, by reacting alkyl (4-halomethyl)iminobenzoates of the formula <IMAGE> or their HCl or HBr salts, R denoting C1-C4-alkyl or C1-C4-alkoxyethyl and X denoting Cl or Br, with o-aminophenol, o-aminothiophenol or o-phenylenediamine and allowing the 2-benz(ox, othi or imid)azol-4-ylhalomethylbenzenes obtained thereby to react with an approximately equivalent amount of sodium tert.-butylate. The stilbene compounds obtained thereby are used as optical brighteners.
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