US3725413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of ethyl 8-hydroxy-1,3-dioxolo{8 4,5g{9 -quinoline-7-carboxylate
Assignee: Warner Lambert Co LLC
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Filing: 1972-01-17
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Granted: 1973-04-03
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Expires: 1992-01-17
Abstract
Abstract A process for the production of ethyl 8-hydroxy-1,3dioxolo(4,5g)-quinoline-7-carboxylate is disclosed. This process comprises reacting ethyl alcohol with phosphorous pentoxide under carefully controlled temperature conditions using xylene as the vehicle. To this reaction mixture is added diethyl (3,4methylenedioxyphenyl)-aminomethylenemalonate which is then heated at 138* to 140* C. for about 60 minutes to produce the desired product. Ethyl 8-hydroxy 1,3-dioxolo(4,5g)-quinoline-7carboxylate is useful as an intermediate for the production of oxolinic acid.
Inventors
- 👤 J Genzer
- 👤 G Conrad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:57
CPC Classifications
C; C07; C07D; C07D491/00; C07D491/02; C07D491/04; C07D317/00; C07D317/08; C07D317/44; C07D317/46; C07D317/48; C07D317/62; C07D317/66
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
25 words
A method according to claim 1 wherein said ethyl alcohol, phosphorus pentoxide and diethyl(3,4-methylenedioxyphenyl)-aminomethylenemalonate are employed approximately at a molar ratio of about 3.53:2.6:1 respectively.
Claim 2
Dependent Claim
16 words
A method according to claim 1 wherein said base is a 50 percent sodium hydroxide solution.
Claim 3
Dependent Claim
12 words
A method according to claim 1 wherein said base is ammonium hydroxide.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |