2,4-Dichlorobenzoyl chloride → HCID 178456657, compound

Participants

Reaction Steps

A suspension of 1.4 g. of 1-allyl-3-methyl-2-pyrazolin-5-one and 0.74 g. of calcium hydroxide in 20 ml. of isopropanol is heated under reflux with stirring for 1.5 hours. After cooling, to the resulting mixture is added dropwise 2.3 g. of 2,4-dichlorobenzoyl chloride. After completion of the dropwise addition, the resulting mixture is heated under reflux for 5.5 hours. After completion of the reaction, the solvent is distilled off from the reaction mixture and to the residue is added 3 ml. of 2 N hydrochloric acid to adjust pH to 3.0. Then, the mixture is extracted with chloroform and the extract solvent is distilled off from the extract. The residue is dissolved in a small amount of benzene and the solution is washed with water, dried over anhydrous sodium sulfate and the solvent is distilled off. The resulting residue is recrystallized from isopropyl ether containing a small amount of methylene chloride to give 1.18 g. of the desired product as white crystals melting at 161°-163° C. Yield 40.7%.

Provenance & Evidence