Isoamyl Nitrite → 1-(2,4-Difluorophenyl)-N-ethyl-4-nitroso-1H-pyrazol-5-amine

Participants

Reaction Steps

A solution of 1-(2,4-difluorophenyl)-N-ethyl-1H-pyrazol-5-amine (1.15 g, 5.16 mmol) in 4.0 mL of EtOAc, 2.0 mL of EtOH and 4.0 mL of 5-6 N HCl in 2-propanol was cooled in an ice/brine bath and treated with isoamyl nitrite (0.70 mL, 5.28 mmol) drop wise. After stirring at this temperature for 15 min, the reaction was quenched by the addition of 28-30% NH4OH solution and EtOAc, forming a deep blue solution. The EtOAc layer was separated, washed with brine, dried and concentrated to afford the title compound as a brown crystalline solid. MS (ES+): 253.1 (M+H)+.

Provenance & Evidence