Patent US3903169A successfully refreshed from Google Patents.
US3903169A
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Process of reacting cyclopentanone with lactones
Assignee: Polaroid Corp
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Filing: 1973-08-27
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Granted: 1975-09-02
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Expires: 1993-08-27
Abstract
Abstract A process for preparing a silver halide developer of the following formula: 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 an improved condensation reaction between a cyclopentanone anion and a lactone to directly provide an intermediate which can be readily converted to the dye developer of formula 1.
Inventors
- 👤 Henry Bader
- 👤 Avinash C Mehta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:30
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/56; C07C45/57; C07C45/60; C07C45/61; C07C45/67; C07C45/673; C07F; C07F1/00; C07F1/02; C07F3/00; C07F3/02; 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: 14
Claim 1
Independent Claim
18 words
A PROCESS WHICH COMPRISES THE STEPS OF A. REACTING AN EXCESS OF A CYCLOPENTANONE ANION OF TE FORMULA:
Claim 2
Dependent Claim
18 words
A PROCESS WHICH COMPRISES THE STEPS OF A. REACTING AN EXCESS OF A CYCLOPENTANONE ANION OF TE FORMULA:
Claim 3
Dependent Claim
13 words
A process of claim 1 wherein said cyclopentanone anion conforms to the formula
Claim 4
Dependent Claim
26 words
A process of claim 1 wherein said excess of cyclopentanone anion is an amount between about 1.2 to about 2.5 times the amount of lactone employed.
Claim 5
Dependent Claim
9 words
A process of claim 1 wherein M is Li.
Claim 6
Dependent Claim
9 words
A process of claim 1 wherein M is MgX.
Claim 7
Dependent Claim
12 words
A process of claim 1 wherein said lactone conforms to the formula:
Claim 8
Dependent Claim
9 words
A process of claim 6 wherein R3 is hydrogen.
Claim 9
Dependent Claim
8 words
A process of claim 6 wherein R3 is
Claim 10
Dependent Claim
9 words
A process of claim 6 wherein R3 is CH3OCH2-.
Claim 11
Dependent Claim
15 words
A process which comprises the steps of (a) reacting a cyclopentanone anion of the formula
Claim 12
Dependent Claim
15 words
A process which comprises the steps of (a) reacting a cyclopentanone anion of the formula
Claim 13
Dependent Claim
9 words
A process of claim 10 wherein M is Li.
Claim 14
Dependent Claim
11 words
A process of claim 10 wherein M is MgCl or MgBr.
References Cited (Backward Citations)
US3772368A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |