The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 02, 1985
Filed:
Apr. 25, 1983
Lorenz Heiss, Hofheim am Taunus, DE;
Hoechst Aktiengesellschaft, , DE;
Abstract
A process for the preparation of 4,4'-bis[benz(ox, othi or imid)azol-2-yl]stilbenes of the formula ##STR1## in which R, R.sup.1, R.sup.2 and R.sup.3 are identical or different and denote hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -alkoxycarbonyl, chlorine, bromine, nitro or sulfo and X denotes oxygen, sulfur or NH, by reacting alkyl (4-halomethyl)iminobenzoates of the formula ##STR2## or their HCl or HBr salts, R denoting C.sub.1 -C.sub.4 -alkyl or C.sub.1 -C.sub.4 -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.