反应详情

To conc. sulfuric acid (3 ml) is added sodium nitrite (0.3 g). The mixture is stirred at.70° C. for 10 minutes and then cooled to below 40° C. and thereto a solution of 2,3,5-trifluoro-4-methylaniline (0.48 g) in acetic acid (5 ml) is added dropwise below 40° C. After stirring for 30 minutes, the reaction mixture is added dropwise to a solution of copper (I) chloride (1.04 g) in conc. hydrochloric acid (10.4 ml) and the mixture is stirred at 80° C. for 30 minutes and then cooled. The resultant is poured into ice-water, extracted with dichloromethane, and the extract is .washed with water and dried. The solvent is distilled off under reduced pressure and purified by silica-gel column-chromatography (eluent; dichloromethane: n-hexane =1 : 4) to give 2,3,6-trifluoro-4-chlorotoluene (0.22 g).

1. temperaturecooled to below 40° C.
2. stirringAfter stirring for 30 minutes
3. stirringthe mixture is stirred at 80° C. for 30 minutes
4. temperaturecooled
5. extractionextracted with dichloromethane
6. customdried
7. distillationThe solvent is distilled off under reduced pressure
8. custompurified by silica-gel column-chromatography (eluent; dichloromethane: n-hexane =1 : 4)