1-Methylpiperazine → Amifloxacin

Participants

Reaction Conditions

Reaction Steps

The compound of Example 1 was prepared on a still larger scale as follows: A mixture of 970 g of 7-chloro-6-fluoro-1,4-dihydro-1-methylamino-4-oxo-3-quinolinecarboxylic acid, 1600 ml of N-methylpiperazine and 8 liters of 2-methoxyethanol was heated to reflux (about 127° C.) over a period of three hours. After 20 hours at reflux, the reaction mixture was cooled to 10° C. and filtered. The filter cake was washed with cold methoxyethanol, followed by methanol. The product was dried at 40° C., affording 925 g of 6-fluoro-1,4-dihydro-1-methylamino-7-(4-methyl-1-piperazinyl)-4-oxo-3-quinolinecarboxylic acid which was purified in the form of its methanesulfonate salt.

Provenance & Evidence