Acetic Acid → 3-(5-Nitrofuran-2-yl)-1-phenyl-1H-pyrazole-4-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

Add 0.1 g of glacial acetic acid and 4.0 g of phenylhydrazine to a solution of 5.0 g of 5-nitro-2-acetylfuran in 27 ml of dimethylformamide, the temperature rising slightly. Stir the resulting admixture for 1 hour without heating before clarifying with degased active charcoal and then adding 16.3 g of phosphorus oxychloride to the thus-prepared solution of 5-nitro-2-acetylfuran-phenylhydrazone while cooling with ice at from 10° to 15° C. Stir for a further hour at this temperature and then for 24 hours at room temperature. Pour the solution (containing 4-pyrazolylmethylenedimethylammonium salt) onto ice and water and then heat for 1.5 hours at 40° C before cooling in ice to obtain an 85% yield of 3-(5-nitro-2-furyl)-1-phenylpyrazole-4-carboxaldehyde [m.p. 208° to 209° C (dimethylformamide/water)].

Provenance & Evidence