US3963736A
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US
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Preparation of 1-(lower alkyl)-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylic acids
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1974-06-10
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Granted: 1976-06-15
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Expires: 1994-06-10
Abstract
Abstract A process for producing a compound of the formula: ##SPC1## Wherein Z is CH or N; R is a lower alkyl group, a lower alkenyl group, a cycloalkyl group or a hydroxyalkyl group; R 1 is a hydrogen atom or lower alkyl group; when Z is N, R 2 , R 3 and R 4 are a hydrogen atom, a halogen atom a lower alkyl group, a lower alkoxyl group, a lower hydroxyalkyl group, a lower acyloxyalkyl group, trihalogenoalkyl group, a carboxyl group, a cyano group, or an aralkyl group; when Z is CH, R 2 , R 3 and R 4 are a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxyl group, a trihalogenoalkyl group, a cyano group, a nitro group, an alkylmercapto group, a lower alkylenedioxy group, or a lower alkylene bridge attached to the quinoline nucleus, which comprises heating a compound of the formula ##SPC2## Wherein R, R 1 , R 2 , R 3 , R 4 and Z are as defined above, followed, if desired, by hydrolyzing the product obtained, is disclosed. The product is useful as an antibacterial agent. An intermediate having the formula: ##SPC3## Wherein A is OR or a halogen atom, and R, R 1 , R 2 , R 3 , R 4 and Z are as defined above, and a process for its preparation are also disclosed.
Inventors
- 👤 Takenari Nakagome
- 👤 Hideo Agui
- 👤 Toru Mitani
- 👤 Mitsuo Nakashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:02
CPC Classifications
C; C07; C07D; C07D471/00; C07D471/02; C07D471/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
217 words
A process for the production of a 1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylic acid represented by the formula I ##SPC10## wherein R is a C 1 -C 4 alkyl group, which process comprises a. reacting the compound represented by the formula II ##SPC11## with a halogenating agent to provide the compound represented by the formula III ##SPC12## b. reacting the compound III so formed in the presence of a base selected from the group consisting of an alkali metal hydroxide, an alkali metal carbonate, a metal salt of an alcohol represented by the formula ROH wherein R is as described above and pyridine with an alcohol represented by the formula ROH wherein R is as described above, to provide a compound represented by the formula IV ##SPC13## wherein R is as described above: c. heating the compound IV in the presence of absence of an alkylating agent or an acid to provide a compound represented by the formula V, wherein said alkylating agent is an alkyl halide, an alkenyl halide, an alkyl p-toluene sulfonate, a cycloalkyl halide, an hydroxy alkyl halide, a dialkyl sulfate or triethyloxonium fluoroborate and wherein said acid is a strong, non- oxidizing inorganic or organic acid or a Lewis acid ##SPC14## and d. then hydrolyzing the compound V to provide a 1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-caboxylic acid represented by the formula I.
Claim 2
Dependent Claim
217 words
A process for the production of a 1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylic acid represented by the formula I ##SPC10## wherein R is a C 1 -C 4 alkyl group, which process comprises a. reacting the compound represented by the formula II ##SPC11## with a halogenating agent to provide the compound represented by the formula III ##SPC12## b. reacting the compound III so formed in the presence of a base selected from the group consisting of an alkali metal hydroxide, an alkali metal carbonate, a metal salt of an alcohol represented by the formula ROH wherein R is as described above and pyridine with an alcohol represented by the formula ROH wherein R is as described above, to provide a compound represented by the formula IV ##SPC13## wherein R is as described above: c. heating the compound IV in the presence of absence of an alkylating agent or an acid to provide a compound represented by the formula V, wherein said alkylating agent is an alkyl halide, an alkenyl halide, an alkyl p-toluene sulfonate, a cycloalkyl halide, an hydroxy alkyl halide, a dialkyl sulfate or triethyloxonium fluoroborate and wherein said acid is a strong, non- oxidizing inorganic or organic acid or a Lewis acid ##SPC14## and d. then hydrolyzing the compound V to provide a 1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-caboxylic acid represented by the formula I.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein process step (c) is carried out by heating compound (IV).
Claim 4
Dependent Claim
27 words
The process of claim 1 wherein process step (c) is carried out in the presence of an acid catalyst and in the absence of an alkylating agent.
Claim 5
Dependent Claim
27 words
The process of claim 1 wherein process step (c) is carried out in the presence of an alkylating agent and in the absence of an acid catalyst.
Claim 6
Dependent Claim
18 words
The process of claim 1 wherein the base utilized in process step (b) is an alkali metal hydroxide.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein the base utilized in process step (b) is an alkali metal carbonate.
Claim 8
Dependent Claim
23 words
The process of claim 1 wherein the alkylating agent is used in process step (c), said alkylating agent being a lower alkyl halide.
Claim 9
Dependent Claim
23 words
The process of claim 1 wherein the alkylating agent is used in process step (c), said alkylating agent being a lower alkyl sulfate.
Claim 10
Dependent Claim
20 words
The process of claim 1 wherein an acid is used in process step (c), said acid being an organic acid.
Claim 11
Dependent Claim
20 words
The process of claim 1 wherein an acid is used in process step (c), said acid being a Lewis acid.
Claim 12
Dependent Claim
28 words
The process of claim 1 wherein the product of each of steps (a), (b) and (c) is isolated prior to proceeding with the next step of the process.
References Cited (Backward Citations)
US3673193A
Cited
US3855232A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-15 | 1979-12-15 | 1980-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-15 | 1983-12-15 | 1984-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-15 | 1987-12-15 | 1988-06-15 | $7700.00 | Window Closed / Lapsed |