3-Bromo-1-propanol → 3-(3,5-Dibromo-4-nitropyrazol-1-yl)propan-1-ol

Participants

Reaction Conditions

Reaction Steps

A mixture of 3,5-dibromo-4-nitropyrazole (2) (2.0 g; 7.38 mmol) in DMF (9.5 ml) was added over 15 minutes to a suspension of NaH (0.32 g, 8.0 mmol; 60% dispersion in oil, prewashed with hexane) in DMF (16 ml) with stirring and under an inert atmosphere. After stirring for 15 minutes, a solution of 3-bromo-1-propanol (1.0 g; 7.19 mmol) in DMF (3.2 ml) was added dropwise. The reaction mixture was heated at 80° C. for 2 hours (monitored by TLC) and the DMF was then evaporated off under reduced pressure. A mixture of DCM/water (20 ml, 1/1) was added. The organic phase was dried over Na2SO4 and the solvent was evaporated off under reduced pressure. The crude reaction product was obtained as a black oil (1.9 g, 79%), which was used without further purification in the amination step.

Provenance & Evidence