Carbon Dioxide → 3-Chloromethylthio-7-fluoro-1-methyl-4-quinolone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

3.59 g (5 mmole) of racemic flosequinan (1) were added (over the course of one minute) to a mixture of thionyl chloride (12 ml) and pyridine (3 ml) with efficient stirring and gentle cooling in a bath of dry ice and acetone, to keep the temperature in the range of 0° C. to 6° C. The mixture was stirred at approximately 0° C. for 5 minutes, cooled to −5° C. and poured as a thin stream into 350 ml of ice-water with efficient stirring. After 10 minutes of stirring at 0° C., a solid was filtered off, washed with water and dried over phosphorous pentoxide, under high vacuum producing 2.82 g (74% yield) of 95% pure (by 1H NMR) 3-chloromethylthio-7-fluoro-1-methyl-4-quinolone (6). 1H NMR, CDCl3, δ=8.50 dd, 1H, J=6.6 & 9.0 Hz, H at C5; 8.01 s, 1H, H at C2; 7.18 ddd, 1H, J=2.1 & 9.0 & 10.2 Hz, H at C6; 7.09 dd, 1H, J=2.1 & 10.2 Hz, H at C8; 5.01 s, 2H, CH2; 3.83 s, 3H, N—CH3.

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