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.
本文披露了制备6-(较低烷氧基)-5-(三
氟甲基)-
1-萘甲酸衍
生物的过程和中间体。这些衍
生物可用于制备醛糖还原酶
抑制剂。关于该过程,1,1,1-三
氟-5-(2-甲基苯基)-
2,3-戊二酮3-
肟被环化成为关键中间体3,4-二氢-1-羟基-5-甲基-1-(三
氟甲基)-2(1H)-
萘酮
肟;而3,4-二氢-1-羟基-5-甲基-1-(三
氟甲基)-2(1H)-
萘酮则通过脱
水剂芳构化为5-甲基-1-(三
氟甲基)-
2-萘酚。