Triethylamine → (RS)-7-fluoro-1-methyl-8-[3-(4-methylphenyl)-1-piperazinyl]-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine-3-carboxylic acid

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Reaction Conditions

Reaction Steps

A suspension of 8-chloro-7-fluoro-1-methyl-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine-3-carboxylic acid (1.84 g) in pyridine (20 cc), (RS)-2-(4-methylphenyl)piperazine (5.83 g) and triethylamine (1.24 g) is heated to a temperature in the region of 115° C. for 37 hours. After cooling to approximately 20° C., the insoluble matter is drained and washed with ethanol (2×5 cc) and ethyl ether (2×5 cc). After recrystallization in dimethylformamide (25 cc), (RS)-7-fluoro-1-methyl-8-[3-(4-methylphenyl)-1-piperazinyl]-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine-3-carboxylic acid (0.8 g) is obtained in the form of a yellow solid, decomposing at 282° C.

Provenance & Evidence