Process for the preparation of 3-[2'H-benzotriazol-(2')-yl]-4-hydroxy-benzenesulfonic acids and the salts thereof
US4937349A · kind A · utility
6Cited by
2References
5Claims
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Key dates
| Filing date | Oct 19, 1988 |
| Grant date | Jun 26, 1990 |
| Priority date | — |
| Expiry date | Oct 19, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D249/20
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
There is disclosed a process for the preparation of 3-[2'H-benzotriazol-(2')-yl]-4-hydroxybenzenesulfonic acids and salts thereof of formula ##STR1## wherein R is hydrogen or chlorine, PA0 R.sub.1 is branched or straight chain C.sub.1 -C.sub.12 alkyl or phenyl-C.sub.1 -C.sub.3 alkyl, and PA0 M is hydrogen sodium or potassium, which process comprises sulfonating a 2-(2'-hydroxy-5'-tert-butylphenyl)-benzotriazole of formula ##STR2## wherein R and R.sub.1 are as defined above, and neutralizing the final product to pH 7. In the sulfonation, the tert-butyl group is replaced by the --SO.sub.3 H group with elimination of isobutylene.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.