Water → HCID 21852672, compound

Participants

Reaction Steps

0.25 g (0.005 mol) of 4-dimethylaminopyridine and 4.25 g (0.042 mol) of triethylamine are added to 11.0 g (0.046 mol) of 4-chloro,3-(2,2-difluorobenzo-1,3-dioxol-4-yl)-1H-pyrazole (prepared as described in patent PH 91-033) dissolved in 100 ml of THF. A solution of 3.6 g (0.046 mol) of acetyl chloride in 50 ml of THF is run dropwise and at 0° C. onto this solution. Stirring is continued for 3 h at room temperature. The reaction mixture is poured into 300 ml of water and extracted with ethyl acetate. After drying the organic phase and concentration under vacuum, the residue is triturated with 50 ml of heptane, filtered and dried. We obtain 12.8 g of 1-acetyl-4-chloro-3-(2,2-difluorobenzo-1,3-dioxol-4-yl)pyrazole melting at 131° C.

Provenance & Evidence