Hydrochloric Acid → 6-Ethoxy-4-(4-methoxyanilino)-7-methyl-1,8-naphthyridine-3-carboxylic acid

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Reaction Steps

A mixture ethyl 6-ethoxy-4-(4-methoxyanilino)-7-methyl-1,8-naphthyridine-3-carboxylate (6.38 g), water (40 ml), sodium hydroxide solution (120 ml, 0.6M) was boiled and stirred under reflux for 2 hours and then allowed to cool. The mixture was acidified with 5M hydrochloric acid (100 ml) and filtered. The filtrate was extracted with dichloromethane to give a residue which was washed with 5M hydrochloric acid and filtered to give 6-ethoxy-4-(4-methoxyanilino)-7-methyl-1,8-naphthyridine-3-carboxylic acid, m.p. 259°-263° C.

Provenance & Evidence