Hydrochloric Acid → 1-(3-Bromo-phenyl)-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid

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Reaction Steps

A suspension of ethyl 1-(3-bromophenyl)-1,4-dihydro[1,8]naphthyridin-4-one-3-carboxylate from Step 1 (1 eq) in a mixture of tetrahydrofuran-methanol (0.15M) and 1N aqueous sodium hydroxide (2 eq) was heated at ca 50° C. with stirring for 20 minutes. After cooling, the mixture was diluted with water and acidified with 1N aqueous HCl. After stirring for 45 minutes, the precipitate was filtered, washed well with water and dried to afford the title acid as a cream-colored solid.

Provenance & Evidence