Trityl chloride → Dimethyl 1-trityl-3,5-pyrazoledicarboxylate

Beteiligte Stoffe

Reaktionsschritte

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°.

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