Chloroform → 2-Chloro-6,7,8-trifluoro-3-formyl-1,4-dihydroquinoline

Participants

Reaction Conditions

Reaction Steps

Phosphoryl chloride (50 cc) is added in the course of 40 minutes with stirring at between 5° and 10° C. to a mixture of trichloromethane (525 cc) and dimethylformamide (49 cc), the mixture is stirred for 15 minutes at this temperature and the temperature is allowed to rise to approximately 20° C. To the solution obtained, 6,7,8-trifluoro-3,4-dihydrocarbostyril (46.8 g) is added gradually in the course of 20 minutes at approximately 20° C. with vigorous stirring. The mixture is left stirring for 30 minutes at a temperature in the region of 20° C., heated to approximately 60° C. and maintained at the same temperature for 2 hours and a half. The reaction mixture is concentrated under reduced pressure (20 kPa) at approximately 50° C. The oily residue is poured with vigorous stirring into ice (500 g). Sodium acetate (100 g) is added in small portions in the course of 30 minutes. The suspension obtained is poured in the course of 15 minutes with vigorous stirring into water (1 liter) heated beforehand to approximately 90° C., and the mixture is stirred for a further 15 minutes at the same temperature. The insoluble matter is drained at approximately 90° C. and washed with water (3×250 cc). 2-Chloro-6,7,8-trifluoro-3-formyl-1,4-dihydroquinoline (47.7 g) is obtained in the form of a colorless solid, decomposing at 220° C.

Provenance & Evidence