反应详情

To a solution of 1.84 g. (10 mmol) of 3,5-pyrazoledicarboxylic acid dimethyl ester* in 15 ml. of DMF, stirred at 0° under argon, was added 480 mg. (10 mmol) of 50% NaH (suspension in mineral oil). After the evolution of hydrogen had ceased, 2.7 g. (10 mmol) of triphenylmethyl chloride in 20 ml. of DMF was added dropwise. The mixture was allowed to warm to room temperature, stirred 1.5 hours, poured into H2O, and the resulting precipitate filtered. After recrystallization from 2-ethoxyethanol-H2O, there was obtained the end product. The analytical sample was obtained as colorless needles by recrystallization from DMF-H2O; mp 212°-213.5°.

1. additionwas added 480 mg
2. filtrationthe resulting precipitate filtered
3. customAfter recrystallization from 2-ethoxyethanol-H2O
4. customthere was obtained the end product