US3772368A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical synthesis
Assignee: Polaroid Corp
•
Filing: 1971-07-19
•
Granted: 1973-11-13
•
Expires: 1991-07-19
Abstract
Abstract A PROCESS FOR PREPARING A SILVER HALIDE DEVELOPER OF THE FOLLOWING FORMULA: 1-((2,5-DI(HO-),R1-PHENYL)-C(-R1)2-C(-R1)2-CO-),R1-CYCLO- PENTAN-2-ONE WHEREIN R1 REPRESENTS A SUBSTITUENT WHICH CAN BE THE SAME OR DIFFERENT BUT WHICH DOES NOT IMPAIR THE FUNCTIONALITY OF THE COMPOUND AS A SILVER HALIDE DEVELOPER. SPECIFIC SUBSTITUENTS INCLUDE HYDROGEN, ALKYL RADICALS AND ALKOXY RADICALS AMONG OTHERS. ESSENTIALLY THE PROCESS INVOLVES THE ACYLATION OF SCHIFF BASE ANIONS WITH LACTONES TO DIRECTLY PROVIDED AN INTERMEDIATE WHICH CAN BE READILY CONVERTED TO THE DYE DEVELOPER OF FORMULA 1.
Inventors
- 👤 H Bader
- 👤 A Mehta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:32
CPC Classifications
C; C07; C07D; C07D309/00; C07D309/02; C07D309/08; C07D309/10; C07D309/12; C07C; C07C45/00; C07C45/51; C07C45/516; C07C45/56; C07C45/57; C07C45/60; C07C49/00; C07C49/587; C07C49/703; C07C49/747; C07C49/753; C07D311/00; C07D311/02; C07D311/04; C07D311/06; C07D311/20; G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/30; G03C5/3021; G03C8/00; G03C8/02; G03C8/08; G03C8/10; G03C8/12; G03C8/14; G03C8/16; G03C8/18
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |