HCID 20071620, compound → HCID 20071612, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of 6 g of 8-chloro-3-ethoxycarbonyl-1-ethoxymethyl-7-fluoro-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine in 120 cm3 of water, 120 cm3 of ethanol and 47.5 cm3 of 2N aqueous potassium hydroxide solution is heated, with stirring, at a temperature close to 75° C. for 2 hours and a half. A small amount of insoluble matter is removed by filtering at the same temperature. After cooling to about 20° C., 6 cm3 of acetic acid are added to the filtrate. The precipitate obtained is drained, washed with 3 times 20 cm3 of water and recrystallized from 60 cm3 of dimethylformamide. 4 g of 8-chloro-1-ethoxymethyl-7-fluoro-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine-3-carboxylic acid are obtained in the form of a yellow solid which decomposes at 285° C.

Provenance & Evidence