反应详情

A solution of 4.3 g (0.015 mol) of 6,7-dichloro-1-ethyl-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid and 9 g of 1-methylpiperazine in a mixture of methyl cellosolve (45 cm3) and dimethylformamide (10 cm3) was heated to reflux temperature. After 6 hours, 75% of the theoretical amount of ionized chlorine (1 atom) had been released into the mixture. Heating was continued for a further 2 hours. The solution was concentrated to dryness in vacuo. The residue was taken up in 20 cm3 of ethanol. The solid, which was filtered off and recrystallised from methyl cellosolve, gave 2.78 g of 6-chloro-1-ethyl-7-(4-methylpiperazinyl)-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid, m.p. 260° C., which was identical to the compound described in Example 1.

1. temperaturewas heated
2. temperatureto reflux temperature
3. temperatureHeating
4. waitwas continued for a further 2 hours
5. concentrationThe solution was concentrated to dryness in vacuo
6. filtrationThe solid, which was filtered off
7. customrecrystallised from methyl cellosolve