Sulfur-containing aromatic tetracarboxylic acids and derivatives thereof
US5126462A · kind A · utility
3Cited by
4References
7Claims
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Key dates
| Filing date | Jun 12, 1990 |
| Grant date | Jun 30, 1992 |
| Priority date | — |
| Expiry date | Jun 12, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D307/89
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Aromatic tetracarboxylic acids or derivatives thereof of the general formula I ##STR1## in which R denotes a divalent radical of the formula II ##STR2## Ar denotes tri- or tetravalent aromatic radicals or mixtures thereof, X, if Ar is trivalent, denotes an amide radical, and if Ar is tetravalent denotes an imide radical, and Y and Z either together denote the anhydride radical --CO--O--CO-- or by themselves and independently of one another denote the radicals --COOH, --COCL or --COOR.sub.1, and a process for their preparation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.