Pyridine → 5-Acetamido-3-bromo-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole

Pyridine (4.0 ml) was added dropwise to a stirred solution of 5-amino-3-bromo-1-(2,6-dichloro-4-trifluoromethylphenyl)-pyrazole (5.0 g), acetyl chloride (3.0 g) and dry chloroform (30 ml), causing an exothermic reaction (maximum temperature 60° C.). The reaction mixture was stirred at laboratory temperature for 2 h and evaporated to dryness. The residue was dissolved in ethanol (25 ml), ammonia solution (d. 0.880; 25 ml) was added, and the solution was boiled under reflux for 1 h. The cooled reaction mixture was evaporated to dryness, dissolved in dichloromethane (100 ml), washed with dilute hydrochloric acid (3×50 ml) and water (50 ml), dried over anhydrous magnesium sulphate, filtered, and evaporated to give 5-acetamido-3-bromo-1-(2,6-dichloro-4-trifluoromethylphenyl)-pyrazole (5.3 g), m.p. 180°-187° C., in the form of a pale brown solid.

1. customan exothermic reaction (maximum temperature 60° C.)
2. customevaporated to dryness
3. dissolutionThe residue was dissolved in ethanol (25 ml)
4. additionammonia solution (d. 0.880; 25 ml) was added
5. temperatureunder reflux for 1 h
6. customThe cooled reaction mixture
7. customwas evaporated to dryness
8. dissolutiondissolved in dichloromethane (100 ml)
9. washwashed with dilute hydrochloric acid (3×50 ml) and water (50 ml)
10. dry with materialdried over anhydrous magnesium sulphate
11. filtrationfiltered
12. customevaporated

ORD record

ord-7ed6f2b836024b4188db816338bc2697

Source dataset

uspto-grants-1993_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05232940