Hydrochloric Acid → 5-Amino-4-nitroso-1-phenylpyrazole

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-phenyl-2H-pyrazol-3-ylamine (250 mg, 1.57 mmol) in EtOH (3 mL) is added HCl (4N in dioxane, 1.15 mL, 4.6 mmol). The mixture is then cooled down to −10° C., tert-butyl nitrite (178 mg, 1.73 mmol) is added drop wise. After addition, the mixture is stirred at 0° C. for 1 h. The precipitate is collected by filtration to provide 4-nitroso-2-phenyl-2H-pyrazol-3-ylamine (180 mg, 60%) as yellow solid.

Provenance & Evidence