Synthesis of pyrazolotriazole photographic dye forming color couplers and intermediates
US5998629A · kind A · utility
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13Claims
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Key dates
| Filing date | Dec 2, 1998 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Dec 2, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/3835
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Photographic pyrazolotriazole dye forming coupler compound or coupler intermediate compounds can be readily prepared by inducing an elimination-addition reaction between certain pyrazolotriazole compounds and aromatic amines in the presence of an inorganic base or formate. Yields and purity are high, and reaction time is reduced with the specific set of conditions and reactants, and environmental impact from waste is reduced. The resulting compounds can be used themselves as photographic dye forming couplers or further reacted to prepare useful coupler compounds for photographic use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.