Methods for the preparation of tris-aryl-o-hydroxyphenyl-s-triazines
US6242598A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2000 |
| Grant date | Jun 5, 2001 |
| Priority date | — |
| Expiry date | Mar 22, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D251/24
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for preparing 2-(2,4-dihydroxyphenyl)-4.6-diaryl-s-triazines in three steps starting with cyanuric chloride is described. Step 1 involves the nucleophilic (basic) displacement of one chlorine atom with a phenolic moiety. Step 2 involves a Friedel-Crafts reaction using a Lewis acid catalyst (preferably aluminum chloride) to replace the remaining two chlorine atoms with aryl groups such as xylyl. Finally, step 3 involves replacing the phenolic moiety with resorcinol using either a Lewis acid or protic acid catalyst or combinations thereof. Some additional processes only peripherally related to the three-step process outlined above are also described for the preparation of various s-triazine compounds. The s-triazines prepared are useful as UV absorbers for the stabilization of organic substrates against the adverse effects of actinic light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.