反应详情

温度

0 °C

To 1.7 ml (0.01896mol) of trifluoromethane sulfonic acid were added 2.06 mol (0.0189 mol) of anisole and 8.8 ml (0.11378 mol) of trifluoroacetic acid and the mixture was cooled at 0° C. in an ice-sodium chloride bath. With stirring, 2.0 grams (0.0047 mol) of ethyl 7-chloro-6-fluoro-2-(4-methoxybenzylthio)-4-oxo-dihydroquinoline-3-carboxylate was added thereto and the mixture was stirred for about twenty minutes. Then trifluoroacetic acid and anisole were evaporated therefrom under reduced pressure and 15 grams of ice water was added to the residue. Yellow crystals appeared immediately. The crystals were collected by filtration, washed with water, dried, and recrystallized from dimethyl formamide and ether to give ethyl 7-chloro-6-fluoro-2-mercapto-4-oxo-1,4-dihydroquinoline-3-carboxylate. Yellow crystals. Yield 1.4 grams (98 percent). Melting point 221° to 223° C. (decomposition). Elementary analysis calculated as C12H19ClFNO3S: C 47.-7, H 3.01, N 4.64; Found: C 47.81, H 3.25, N 4.81.

1. stirringthe mixture was stirred for about twenty minutes
2. customThen trifluoroacetic acid and anisole were evaporated
3. additionunder reduced pressure and 15 grams of ice water was added to the residue
4. filtrationThe crystals were collected by filtration
5. washwashed with water
6. customdried
7. customrecrystallized from dimethyl formamide and ether