Benzisothiazole-1,1-dioxide and naphtho-1,2-thiazine-1,1-dioxide compounds
US4191689A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1977 |
| Grant date | Mar 4, 1980 |
| Priority date | — |
| Expiry date | Sep 23, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/55
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention relates to certain 3,3-di(4'-OP-carbocyclic aryl)-2,3-dihydrobenz[d]isothiazole-1,1-dioxides (and-2,3-dihydronaphtho[1,8-de]-1,2-thiazine-1,1-dioxides) and to the preparation thereof by reacting (a) at least 2 equivalents of (i) a 4'-OP-carbocyclic aryllithium compound wherein P is a protecting group compatible with organometallic reagents or (ii) a 4'-OP-carbocyclic arylMgE compound wherein P is a protecting group compatible with organometallic reagents and E is chloro, bromo or iodo and (b) 1 equivalent of a compound selected from a 3-chlorobenz[d] isothiazole-1,1-dioxide and a 3-chloronaphtho[1,8-de]-1,2-thiazine-1,1-dioxide to give the corresponding 3,3-di(4'-OP-carbocyclic aryl)-2,3-dihydrobenz[d]isothiazole-1,1-dioxide or the corresponding 3,3-di(4'-OP-carbocyclic aryl)-2,3-dihydronaphtho[1,8-de]-1,2-thiazine-1,1-dioxide, which compounds are useful in the synthesis of phenol and 1-naphthol sulfam(na)-phthaleins employed, for example, as photographic optical filter agents and filter agent precursors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.