US4304720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorescein esters and ethers and the preparation thereof
Assignee: Merck and Co Inc
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Filing: 1980-04-30
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Granted: 1981-12-08
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Expires: 2000-04-30
Abstract
Abstract Fluorescein esters and ethers including the dioleyl derivative of fluorescein are disclosed. These compounds have the useful property of being fluorescent under the influence of the proper frequency of electromagnetic irradiation. Further, dioleyl fluorescein is readily incorporated into low-density lipoproteins which can then become part of the cell matter; the compounds retain their fluorescent properties during this procedure. The fluorescence allows cells to be identified and separated. The fluorescein esters and ethers are prepared from fluorescein and the novel reagent O-alkenyl-N,N'-dialkylisourea.
Inventors
- 👤 Richard T. Dean
- 👤 Conrad P. Dorn, Jr.
- 👤 Tsung-Ying Shen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:56
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/531; G01N33/532; G01N33/533; C; C07; C07C; C07C273/00; C07D; C07D311/00; C07D311/02; C07D311/78; C07D311/80; C07D311/82; Y; Y10; Y10S; Y10S436/00; Y10S436/80
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
27 words
A compound having the formula: ##STR5## wherein R is an alkenyl group of from 12 to 30 carbon atoms with from 1 to 4 cis double bonds.
Claim 2
Dependent Claim
27 words
A compound having the formula: ##STR5## wherein R is an alkenyl group of from 12 to 30 carbon atoms with from 1 to 4 cis double bonds.
Claim 3
Dependent Claim
13 words
The compound of claim 1 wherein the R group contains one double bond.
Claim 4
Dependent Claim
16 words
The compound of claim 2 wherein the R group contains from 16 to 20 carbon atoms.
Claim 5
Dependent Claim
13 words
The compound of claim 3 wherein the R group contains 18 carbon atoms.
Claim 6
Dependent Claim
9 words
The compound of claim 4 which is dioleyl fluorescein.
Claim 7
Dependent Claim
78 words
A process for the preparation of the compound of claim 1 which comprises reacting fluorescein at from 70° to 200° C. for from 2 to 48 hours either without a solvent or in the presence of an inert solvent, with a compound having the formula: ##STR6## wherein R is defined in claim 1 and R 1 and R 2 are independently loweralky of from 1 to 6 carbon atoms or cycloalkyl of from 4 to 6 carbon atoms.
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) | 1984-12-07 | 1985-06-08 | 1985-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-07 | 1989-06-08 | 1989-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-07 | 1993-06-08 | 1993-12-08 | $7700.00 | Window Closed / Lapsed |