Water → 4-Chloro-3-(2,4-dichloro-5-formylphenyl)-5-difluoromethoxy-1-methyl-1H-pyrazole

Participants

Reaction Steps

After addition of 100 ml water to a solution of 3-(5-bromomethyl-2,4-dichlorophenyl)-4-chloro-5-difluoromethoxy-1-methyl-1H-pyrazole (26.60 g, 63.3 mmoles) in 100 ml glacial acetic acid, hexamethylenetetramine (8.87 g, 63.3 mmoles) was added and reacted under reflux for 2 hours. Further, 40 ml conc. sulfuric acid was added and reacted under reflux for 13 hours. Then the reaction product mixture, poured into ice-cold water, was extracted with ethyl acetate. The extract solution was washed with 5% aqueous NaHCO3 and then with water, dehydrated, and concentrated. Purification of the residue by column chromatography gave the title compound (12.66 g), m.p. 138.2° C., yield 56.3%.

Provenance & Evidence