反应详情

A mixture of 1.0 g of 5-amino-1-cyclopropyl-6,7-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid, 1.18 g of 2-methylpiperazine and 10 ml of pyridine was heated under reflux for 3 hours. The reaction mixture was concentrated under reduced pressure, and the residue was dissolved in 28% aqueous ammonia. The solution was neutralized with a 10% aqueous solution of acetic acid and cooled with ice. The crystals were collected by filtration, dissolved in a 10% aqueous solution of acetic acid, treated with activated charcoal, adjusted to pH 8-9 with 29% aqueous ammonia, and cooled with ice. The crystals were collected by filtration and washed successively with water and ethanol to give 0.80 g of 5-amino-1-cyclopropyl-6-fluoro-7-(3-methyl-1-piperazinyl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid. m.p. 181°-183° C.

1. temperaturewas heated
2. temperatureunder reflux for 3 hours
3. concentrationThe reaction mixture was concentrated under reduced pressure
4. dissolutionthe residue was dissolved in 28% aqueous ammonia
5. temperaturecooled with ice
6. filtrationThe crystals were collected by filtration
7. dissolutiondissolved in a 10% aqueous solution of acetic acid
8. additiontreated with activated charcoal
9. temperaturecooled with ice
10. filtrationThe crystals were collected by filtration
11. washwashed successively with water and ethanol