Sodium Carbonate → 5-Chloro-1,3-dimethyl-1h-pyrazole-4-carbonyl chloride

Participants

Reaction Conditions

Reaction Steps

To a solution of 48 g of 5-chloro-1,3-dimethyl-1H-pyrazole-4-carbaldehyde in 195 ml of dichlorobenzene under protective gas are added 39.8 g of sodium carbonate. Subsequently, while illuminating with a mercury lamp, 24 g of chlorine gas are introduced at 20° C. within 3.5 hours. After the gas introduction has ended, the reaction solution is stirred with illumination at 20° C. for a further 20 minutes. The solid is filtered off and washed with a little dichlorobenzene. After the solvent has been removed, 5-chloro-1,3-dimethyl-1H-pyrazole-4-carbonyl chloride is obtained in a yield of 87%.

Provenance & Evidence