Dimethylformamide → HCID 178519879, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of (E)-2-(1-(4-fluorophenyl)ethylidene)hydrazinecarboxamide (1 g, 5.12 mmol, 1.00 equiv) in N,N-dimethylformamide (5 mL) at 5° C. was added phosphorous oxychloride (5 mL) dropwise. The resulting solution was stirred at 70° C. for 2 h. The reaction mixture was cooled to 0° C. and quenched by the addition of 15 mL of ice/water mixture. The pH value of the solution was adjusted to 7 with 4N sodium hydroxide solution. The resulting mixture was stirred at 70° C. for an additional 1 h. The reaction mixture was cooled back to room temperature. The precipitate was collected by filtration and dried in a vacuum oven to give 600 mg (62%) of 3-(4-fluorophenyl)-1H-pyrazole-4-carbaldehyde as a gray solid. LCMS (method A, ESI): RT=1.23 min, m/z=191.0 [M+H]+.

Provenance & Evidence