Reaction #1914813

Reaction equation

isopentyl nitrite

HCl

2-pyridin-2-yl-2H-pyrazol-3-ylamine

isopentyl nitrite

→

4-nitroso-2-pyridin-2-yl-2H-pyrazol-3-ylamine

Yield 81.0%

Solvents

ethanol

Conditions

Workup

1. 1
   Otherto return to ambient temperature
2. 2
   Temperaturethe reaction mixture was cooled to 5° C.
3. 3
   Filtrationfiltered
4. 4
   WashThe solid was washed with absolute MeOH (10 ml)
5. 5
   Otherwas then triturated twice from heptane
6. 6
   OtherThe solid was dried under vacuum at 35° C.

Procedure

HCl (37%, 11 μl) was added to a heterogeneous solution of 2-pyridin-2-yl-2H-pyrazol-3-ylamine (2.2 g, 13.7 mmol) in absolute ethanol (15 ml). The reaction mixture was subsequently cooled to 0° C. and isopentyl nitrite (2.02 ml, 15 mmol) was slowly added. The reaction mixture became dark. After the isopentyl nitrite had been completely added, the reaction mixture was allowed to return to ambient temperature. After 2.5 h at ambient temperature, the reaction mixture was cooled to 5° C. and filtered. The solid was washed with absolute MeOH (10 ml) and was then triturated twice from heptane. The solid was dried under vacuum at 35° C. to give 4-nitroso-2-pyridin-2-yl-2H-pyrazol-3-ylamine (2.1 g, 81%) in the form of a green solid.

Source