Fluorenol catalyzed reduction of o-nitroazobenzenes and 2-aryl-2H-benzotriazole-N-oxides
US5262541A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1992 |
| Grant date | Nov 16, 1993 |
| Priority date | — |
| Expiry date | Dec 15, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D249/20
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for producing 2-aryl-2H-benzotriazole by reducing an o-nitroazobenzene with a saccharide having an aldehyde group as a reducing agent in the presence of fluorenol as a catalyst and a base in solution. The reaction is conducted at a temperature of from about 60.degree. C. to about 80.degree. C. The reaction time and amount of catalyst is significantly reduced compared to the use of an aromatic ketone catalyst. The invention also provides a method for producing 2-aryl-2H-benzotriazole by reducing a 2-aryl-2H-benzotriazole-N-oxide intermediate with a saccharide having an aldehyde group as a reducing agent, in the presence of fluorenol under similar conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.