US3927033A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lasing dye and method of preparation
Assignee: Individual
•
Filing: 1974-11-25
•
Granted: 1975-12-16
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Expires: 1994-11-25
Abstract
Abstract 4-Trifluoromethyl-7-hydroxycoumarin is prepared and disclosed as being useful as a lasing dye in the green to blue-green regions.
Inventors
- 👤 Peter R Hammond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:52
CPC Classifications
C; C09; C09B; C09B57/00; C09B57/02; C07; C07D; C07D311/00; C07D311/02; C07D311/04; C07D311/06; C07D311/08; C07D311/16; H; H01; H01S; H01S3/00; H01S3/14; H01S3/20; H01S3/213
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
1 words
4-TRIFLOUROMETHYL-7-HYDROXYCOUMARIN.
Claim 2
Dependent Claim
1 words
4-TRIFLOUROMETHYL-7-HYDROXYCOUMARIN.
Claim 3
Independent Claim
29 words
A method for preparing 4-trifluoromethyl-7-hydroxycoumarin comprising the steps of: A. DISSOLVING EQUIMOLAR AMOUNTS OF RESORCINOL AND ETHYL 4,4,4-TRIFLUOROACETOACETATE IN DRY BENZENE; B. ADDING PHOSPHORYL CHLORIDE CATALYST; AND C. REFLUXING.
Claim 4
Independent Claim
29 words
A method for preparing 4-trifluoromethyl-7-hydroxycoumarin comprising the steps of: A. DISSOLVING EQUIMOLAR AMOUNTS OF RESORCINOL AND ETHYL 4,4,4-TRIFLUOROACETOACETATE IN DRY BENZENE; B. ADDING PHOSPHORYL CHLORIDE CATALYST; AND C. REFLUXING.
Claim 5
Dependent Claim
16 words
The method according to claim 2 wherein the refluxing step is carried out for 5 hours.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |