Dimethylformamide → 3-(5-Nitrofuran-2-yl)-1-(pyridin-2-yl)-1H-pyrazole-4-carbaldehyde

Participants

Reaction Steps

Add 9.4 g of phosphorus oxychloride dropwise to 16.4 g of anhydrous dimethylformamide at from 10° to 20° C and then stir the obtained reaction mixture for 30 minutes at room temperature before adding thereto (from 35° to 40° C) 5.0 g of 5-nitro-2-acetylfuran-(2-pyridyl)hydrazone. Stir the thus-prepared admixture for 28 hours under nitrogen at this temperature and then pour it and a solution comprising 4-pyrazolylmethylenedimethylammonium salt onto 250 g of ice and water. Heat the resulting reaction mixture for 2 hours at from 30° to 40° C, draw off the formed precipitate and wash the precipitate with water to obtain a 45% yield of 3-(5-nitro-2-furyl)-1-(2-pyridyl)pyrazole-4-carboxaldehyde [m.p. 191° to 191.5° C (from toluene)].

Provenance & Evidence