Dimethylformamide → 5-Chloro-1-ethyl-3-methyl-1H-pyrazole-4-carbaldehyde

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To 28.7 ml of anhydrous N,N-dimethylformamide at 0° C. were added slowly 80.7 ml of phosphorus oxychloride then 15.6 g of 2-ethyl-5-methyl-2H-pyrazol-3-ol. The mixture was stirred under nitrogen at 80° C. for 1 hour, poured into 700 ml of water at 0° C. then extracted six times with 350 ml of diethyl ether. The combined extracts were dried over magnesium sulphate, filtered and evaporated to leave 9.3 g of 5-chloro-1-ethyl-3-methyl-1H-pyrazole-4-carbaldehyde as an orange liquid which was used without further purification.

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