Toluene → Ethyl 1-(4-methoxyphenyl)-5-methyl-1H-pyrazole-4-carboxylate

참여 물질

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반응 단계

Thionyl chloride (3.84 g) was added to a solution of 1-(4-methoxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid (5.0 g) described in Reference Example 5 in toluene (20 ml) at room temperature, stirred at 80° C. for an hour and the solvent and an excess amount of thionyl chloride were evaporated. Pyridine (10 ml) and ethanol (20 ml) were added to the resulting residue and stirred at 40° C. for 0.5 hour. After completion of the reaction, the solvent was evaporated and ethyl acetate and 1N aqueous solution of sodium hydroxide were added. The mixture was extracted with ethyl acetate three times and the organic layer was dried over anhydrous sodium sulfate and concentrated to give 1-(4-methoxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (5.2 g).

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