Piperazine → HCID 67925859, compound

Participants

Reaction Steps

1-Ethyl-7-fluoro-8-(1-piperazinyl)-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine-3-carboxylic acid is prepared under the conditions of Reference Example 5, but starting from 1.6 g of 8-chloro-1-ethyl-7-fluoro-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine-3-carboxylic acid and 4.3 g of piperazine in 20 cm3 of pyridine. After recrystallizing 3 times from, in total, 300 cm3 of dimethylformamide, 0.94 g of 1-ethyl-7-fluoro-8-(1-piperazinyl)-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine-3-carboxylic acid trihydrate is obtained in the form of a yellow solid melting at 320°-322° C.

Provenance & Evidence