Aniline → quinolin-4-ol

Participants

Reaction Steps

In CHART C, carboxylic acid C-1, 3-methyl-3-(4-nitrophenyl)butanoic acid prepared by carbonylation of the corresponding Grignard, is reduced to the corresponding alcohol with borane. The resulting alcohol C-2 is protected as the benzyl ether and the corresponding nitro functionality is reduced to aniline C-3. Heating C-3 with diethyl ethoxymethylenemalonate followed by thermolysis in refluxing diphenylether affords the 4-hydroxyquinoline C-4. Aminolysis of compound C-4 with 4-chlorobenzylamine at about 190 ° C. provides amide C-5 which is then alkylated at the pyridone nitrogen with an alkylhalide and potassium carbonate to afford compound C-6. Deprotection of the benzyl ether under hydrogenolysis conditions affords the desired hydroxyalkyl 4-quinolone carboxamide of formula I of the present invention.

Provenance & Evidence