Photographic coupler and method of making the same
US5264583A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1992 |
| Grant date | Nov 23, 1993 |
| Priority date | — |
| Expiry date | Jun 24, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/30576
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method of forming a washout photographic coupler comprising a coupler moiety (COUP) containing a substituted or unsubstituted ballasted releasing group (A) selected from aryloxy, thioaryloxy, heterocyclicoxy, and thioheterocyclicoxy releasing groups having attached thereto a phenoxy timing group containing a photographically useful group (PUG), the releasing group capable of intramolecular displacement to release the timing group, the method comprising: PA1 (a) providing a coupler moiety (COUP) having the releasing group (A) in a coupling off position, the releasing group (A) having a 2 position containing a carbamyl chloride; PA1 (b) reacting the carbamyl chloride with a phenoxy timing group having an amine blocked with a carbamate group, the reacting being carried out in the presence of a base to form a first product; PA1 (c) removing the carbamate group using an acid to provide a coupler moiety (COUP) having a releasing group (A) and phenoxy timing group having an amine group; and PA1 (d) reacting the amine group to form a carbamyl chloride on the phenoxy timing group before reacting with a photographically useful group to form the washout coupler.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.