反应详情

温度

0 °C

To a suspension of 1,4-dihydro-6,7-dimethoxy-4-oxo-3-quinolinecarboxylic acid (39.9 g, 0.160 mol) in 3.2 l of N,N-dimethylformamide, triethylamine (32.4 g, 0.320 mol) was added. At 0° C. and under nitrogen protection, diphenyl chlorophosphate (43.0 g, 0.160 mol) was added dropwise and the mixture was stirred for 6 hours at 0° C. A solution of N-amino-imidazolidine-2-one (16.2 g, 0.160 mol) in N,N-dimethylformamide was added and stirring was continued at 0° C. overnight. The triethyl ammonium salt (26 g) was filtered off and the filtrate evaporated in vacuo. The residual oil was triturated with 1 l of ethyl acetate and 1 l of water. The resulting solid was filtered off, washed with water and ethyl acetate and dried in vacuo. The crude product was stirred with 270 ml of 0.2N sodium hydroxide solution of 2 days, filtered off, washed with water and dried in vacuo to give 23.2 g of the title compound, melting point>300° C.

1. additionwas added
2. stirringstirring
3. waitwas continued at 0° C. overnight
4. filtrationThe triethyl ammonium salt (26 g) was filtered off
5. customthe filtrate evaporated in vacuo
6. customThe residual oil was triturated with 1 l of ethyl acetate and 1 l of water
7. filtrationThe resulting solid was filtered off
8. washwashed with water and ethyl acetate
9. customdried in vacuo
10. stirringThe crude product was stirred with 270 ml of 0.2N sodium hydroxide solution of 2 days
11. filtrationfiltered off
12. washwashed with water
13. customdried in vacuo