Sodium Hydroxide → HCID 13370522, compound

Participants

Reaction Steps

Following the above procedure, the same methyl ester was brominated in refluxing acetic acid. Methyl 1-methyl-3-(3-trifluoromethylphenyl)-4-bromopyrazole-5-carboxylate thus formed was purified by chromatography over silica gel using methylene dichloride as the eluant. 3.0 g. of 1-methyl-3-(3-trifluoromethylphenyl)-4-bromopyrazole-5-carboxylic acid were obtained (from 8.0 g. of unbrominated ester starting material). The ester was hydrolyzed by the procedure of Example 1 using dilute aqueous sodium hydroxide in aqueous ethanol and the free acid isolated by acidification of the hydrolysis mixture. Recrystallization of the free acid ethanol yielded 1-methyl-3-(3-trifluoromethylphenyl)-4-bromopyrazole-5-carboxylic acid melting at 182°-4° C.

Provenance & Evidence