Sulfuric Acid → 1H-Pyrazole, 1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-3,5-dimethyl-

Reaction equation

[Cl:1][C:2]1[CH:7]=[C:6]([C:8]([F:11])([F:10])[F:9])[CH:5]=[C:4]([Cl:12])[C:3]=1[NH:13][NH2:14].[CH3:15][C:16](=O)[CH2:17][C:18](=O)[CH3:19].S(=O)(=O)(O)O>C(O)C>[CH3:15][C:16]1[CH:17]=[C:18]([CH3:19])[N:13]([C:3]2[C:2]([Cl:1])=[CH:7][C:6]([C:8]([F:9])([F:11])[F:10])=[CH:5][C:4]=2[Cl:12])[N:14]=1

Participants

Procedure

A solution of 2,6-dichloro-4-trifluoromethylphenylhydrazine (5.0 g), 2,4-pentanedione (2.1 ml) and conc. sulphuric acid (0.8 ml) in ethanol (40 ml) was heated under reflux for 20 hours. The ethanol was evaporated under reduced pressure and the residue dissolved in dichloromethane. The extract was washed with sodium bicarbonate solution and brine, dried over magnesium sulphate and evaporated to give 3,5-dimethyl-1-(2,6-dichloro-4-trifluoromethylphenyl)-1H-pyrazole.