US3855232A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of 1-(lower-alkyl)-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylate
Assignee: STWB Inc
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Filing: 1973-06-08
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Granted: 1974-12-17
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Expires: 1993-06-08
Abstract
Abstract Lower-alkyl 4-Q-7-methyl-1,8-naphthyridine-3-carboxylates (I) where Q is chloro or lower-alkoxy are prepared by reacting loweralkyl 1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylate (II) with a chlorinating agent to produce said 4-chloro compound (Ia) which be reaction with alkali metal lower-alkoxide, preferably using lower-alkanol as solvent, produces said 4(lower-alkoxy) compound (Ib). Said 4-chloro compound when heated with alkali metal lower-alkoxide or said 4-(lower-alkoxy) compound when heated yield the known antibacterially active lower-alkyl 1-(lower-alkyl)-1,4-dihydro-7-methyl-4-oxo-1,8naphthyridine-3-carboxylates.
Inventors
- 👤 R Brundage
- 👤 G Lesher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:18
CPC Classifications
C; C07; C07D; C07D471/00; C07D471/02; C07D471/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
19 words
THE PROCESS CONSISTING ESSENTIALLY OF HEAING AT ABOUT 70*-250*C. IN THE ABSENCE OR PRESENCE OF A SUITTING AT ABOUT
Claim 2
Dependent Claim
19 words
THE PROCESS CONSISTING ESSENTIALLY OF HEAING AT ABOUT 70*-250*C. IN THE ABSENCE OR PRESENCE OF A SUITTING AT ABOUT
Claim 3
Dependent Claim
17 words
The process according to claim 1 where the reaction is carried out using lower-alkanol as a solvent.
Claim 4
Dependent Claim
23 words
The process according to claim 1 wherein ethyl 4-chloro-7-methyl-1,8-naphthyridine-3-carboxylate is heated with sodium methoxide using methanol as a solvent to produce methyl 1,4-dihydro-1,7-dimethyl-4-oxo-1,8-naphthyridine-3-carboxylate.
Claim 5
Dependent Claim
43 words
The process consisting essentially of heating at about 70*-250*C. in the absence or presence of a suitable solvent inert under the reaction conditions, where the solvent is selected from a polar, dipolar aprotic, and non-polar solvent, lower-alkyl 4-(lower-alkoxy)-7-methyl-1,8-naphthyridine-3-carboxylate to produce lower-alkyl 1-(lower-alkyl)-1,4-dihydro-7-methyl-4-oxo-1, 8-naphthyridine-3-carboxylate.
Claim 6
Dependent Claim
43 words
The process consisting essentially of heating at about 70*-250*C. in the absence or presence of a suitable solvent inert under the reaction conditions, where the solvent is selected from a polar, dipolar aprotic, and non-polar solvent, lower-alkyl 4-(lower-alkoxy)-7-methyl-1,8-naphthyridine-3-carboxylate to produce lower-alkyl 1-(lower-alkyl)-1,4-dihydro-7-methyl-4-oxo-1, 8-naphthyridine-3-carboxylate.
Claim 7
Dependent Claim
15 words
The process according to claim 4 wherein methyl 4-methoxy-7-methyl-1,8-naphthyridine-3-carboxylate is heated to produce methyl 1,4-dihydro-1,7-dimethyl-4-oxo-1,8-naphthyridine-3-carboxylate.
References Cited (Backward Citations)
US3590036A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |