Process for the preparation of benzotriazoles
US5276161A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1990 |
| Grant date | Jan 4, 1994 |
| Priority date | — |
| Expiry date | Sep 13, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/32
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.