PROCESS FOR PREPARING 6-(LOWER ALKOXY)-5- (TRIFLUOROMETHYL)-1-NAPHTHALENECARBOXYLIC ACID

摘要

A process and intermediates for preparing 6-(lower alkoxy)-5-(trifluoro-methyl)-1-naphthalenecarboxylic acid derivatives are disclosed. The derivatives are useful for preparing aldose reductase inhibitors. With reference to the pro-cess, 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.