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:
Jan. 04, 1994
Filed:
Sep. 13, 1990
Helmut Prestel, Bruchsal, DE;
Rudolf Maul, Lorsch/Hessen, DE;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
2-(2-Hydroxyphenyl)-2H-benzotriazoles of the formula ##STR1## in which R is hydrogen, C.sub.1 -C.sub.12 alkyl or C.sub.1 -C.sub.4 alkoxy, R.sub.1 is hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.6 cycloalkyl, phenyl or phenyl-C.sub.1 -C.sub.4 alkyl and R.sub.2 is C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.6 cycloalkyl, phenyl, phenyl-C.sub.1 -C.sub.4 alkyl or a group --C.sub.n H.sub.2n --COOR.sub.3, in which n is 0 to 4 and R.sub.3 is hydrogen or C.sub.1 -C.sub.12 alkyl, can be prepared particularly advantageously by catalytic hydrogenation of a suitable o-nitroazo compound in the presence of a Pt, Pd, Pt/Pd or Rh hydrogenation catalyst and an alkylenediamine or an acyclic or cyclic polyalkylene polyamine in a halogenated or nonhalogenated aromatic hydrocarbon as solvent.