6-(Lower alkoxy)-5-(trifluoromethyl)-1-naphthalenecarboxaldehydes
US4408077A · kind A · utility
5Cited by
1References
2Claims
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Assignee
Inventors
Key dates
| Filing date | Nov 13, 1981 |
| Grant date | Oct 4, 1983 |
| Priority date | — |
| Expiry date | Nov 13, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C49/223
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.