US4499310A
Expired / Lapsed
US
⏱️ 0.0 years remaining
5-Methyl-1-(trifluoromethyl)-2-naphthalenol, process for its preparation and ethers thereof
Assignee: Wyeth Canada Inc
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Filing: 1983-06-22
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Granted: 1985-02-12
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Expires: 2003-06-22
Abstract
Abstract A process and intermediates for preparing 6-(lower alkoxy)-5-(trifluoromethyl)-1-naphthalenecarboxylic acid derivatives are disclosed. The derivatives are useful for preparing aldose reductase inhibitors. With reference to the process, 1,1,1-trifluoro-5-(2-methylphenyl)-2,3-pentadione 3-oxime is cyclized to give a key intermediate 3,4-dihydro-1-hydroxy-5-methyl-1-(trifluoromethyl)-2(1H)-naphthalenone oxime; and 3,4-dihydro-1-hydroxy-5-methyl-1-(trifluoromethyl)-2(1H)-naphthalenone is aromatized to 5-methyl-1-(trifluoromethyl)-2-naphthalenol with a dehydrating agent.
Inventors
- 👤 Kazimir Sestanj
- 👤 Steven Fung
- 👤 Nedumparambil A. Abraham
- 👤 Francesco Bellini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:24
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/093; C07C17/16; C07C17/26; C07C17/263; C07C17/2632; C07C29/00; C07C29/58; C07C37/00; C07C37/06; C07C37/07; C07C39/00; C07C39/24; C07C39/38; C07C43/00; C07C43/02; C07C43/20; C07C43/225; C07C45/00; C07C45/004; C07C45/42; C07C47/00; C07C47/52; C07C47/575; C07C49/00; C07C49/20; C07C49/213; C07C49/217; C07C49/223
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
52 words
A process for preparing 5-methyl-1-(trifluoromethyl)-2-naphthalenol, which comprises: aromatizing 3,4-dihydro-1-hydroxy-5-methyl-1-(trifluoromethyl)-2(1H)-naphthalenone with a dehydrating agent of the type capable of acylating tertiary alkanols and is one of thionyl bromide, thionyl chloride, phosphorus oxychloride, acetyl chloride, mesyl chloride or acetyl chloride in the presence of an organic proton acceptor, or trifluoroacetic anhydride or acetic anhydride.
Claim 2
Dependent Claim
52 words
A process for preparing 5-methyl-1-(trifluoromethyl)-2-naphthalenol, which comprises: aromatizing 3,4-dihydro-1-hydroxy-5-methyl-1-(trifluoromethyl)-2(1H)-naphthalenone with a dehydrating agent of the type capable of acylating tertiary alkanols and is one of thionyl bromide, thionyl chloride, phosphorus oxychloride, acetyl chloride, mesyl chloride or acetyl chloride in the presence of an organic proton acceptor, or trifluoroacetic anhydride or acetic anhydride.
Claim 3
Dependent Claim
7 words
5-Methyl-1-(trifluoromethyl)-2-naphthalenol and its corresponding lower alkyl ethers.
Claim 4
Dependent Claim
7 words
5-Methyl-1-(trifluoromethyl)-2-naphthalenol and its corresponding lower alkyl ethers.
Claim 5
Dependent Claim
6 words
2-Methoxy-5-methyl-1-(trifluoromethyl)naphthalene, as claimed in claim 2.
References Cited (Backward Citations)
US4408077A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |