反应详情

10 g (0.034 mole) of 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-pyrazole are dissolved in 35 ml of pyridine. 21.4 g (0.068 mole) of 47% chloromethanesulphonyl chloride, dissolved in 1,2-dichlorobenzene, are added dropwise at 0° C. to 5° C. The mixture is stirred for five hours, during which the temperature slowly rises to 20° C. The mixture is then poured into ice-water and extracted with methylene chloride. The organic phase is separated off, washed with dilute hydrochloric acid and extracted three times with 100 ml of saturated sodium bicarbonate solution. The combined aqueous phases are brought to pH 1 with 10% strength hydrochloric acid and the product which has precipitated is taken up in methylene chloride. The methylene chloride phase is separated off, washed with saturated sodium chloride solution, dried over magnesium sulphate and concentrated. 8.7 g (63% of theory) of 5-chloromethanesulphonamido-1-(2,6-dichloro-4-trifluoromethylphenyl)-pyrazole of melting point 63°-66° C. are obtained.

1. additionare added dropwise at 0° C. to 5° C
2. customslowly rises to 20° C
3. extractionextracted with methylene chloride
4. customThe organic phase is separated off
5. washwashed with dilute hydrochloric acid
6. extractionextracted three times with 100 ml of saturated sodium bicarbonate solution
7. customthe product which has precipitated
8. customThe methylene chloride phase is separated off
9. washwashed with saturated sodium chloride solution
10. dry with materialdried over magnesium sulphate
11. concentrationconcentrated