1-Methylpiperazine → 7-Fluoro-1-methylamino-8-(4-methyl-1-piperazinyl)-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine-3-carboxylic acid

Participants

Reaction Steps

The reaction is carried out under the conditions of Reference Example 1 but starting from 1.93 g of 8-chloro-7-fluoro-1-methylamino-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine-3-carboxylic acid, 2.4 g of 1-methylpiperazine and 20 cm3 of pyridine. After recrystallizing twice from 15 cm3 of dimethylformamide each time, 0.9 g of 7-fluoro-1-methylamino-8-(4-methyl-1-piperazinyl)-4-oxo-1,4-dihydro-benzo[b][1,8]-naphthyridine-3-carboxylic acid is obtained in the form of a yellow solid melting at 263°-264° C.

Provenance & Evidence