Sodium hydride → 1-(3,5-Dibromo-4-nitropyrazol-1-yl)propan-2-ol

Temperatur

80 °C

A mixture of 3,5-dibromo-4-nitropyrazole (2) (40.0 g; 147 mmol) in DMF (200 ml) was added over 15 minutes to a suspension of NaH (6.5 g, 162 mmol; 60% dispersion in oil, prewashed with hexane) in DMF (320 ml) with stirring and under an inert atmosphere. After stirring for 35 minutes, a solution of 1-bromo-2-propanol (26.8 ml; 221 mmol) in DMF (80 ml) was added dropwise. The reaction mixture was heated at 80° C. for 2 hours and the DMF was then evaporated off under reduced pressure. A mixture of DCM/water (480 ml, 2/1) was added. The organic phase was extracted with DCM (2×160 ml). The combined organic phases were washed with water (3×400 ml). The organic phase was dried over Na2SO4 and the solvent was evaporated off under reduced pressure. The 1-(3,5-dibromo-4-nitropyrazol-1-yl)-propan-2-ol was obtained as a white solid (23.3 g; 48%).

1. stirringAfter stirring for 35 minutes
2. customthe DMF was then evaporated off under reduced pressure
3. additionA mixture of DCM/water (480 ml, 2/1)
4. additionwas added
5. extractionThe organic phase was extracted with DCM (2×160 ml)
6. washThe combined organic phases were washed with water (3×400 ml)
7. dry with materialThe organic phase was dried over Na2SO4
8. customthe solvent was evaporated off under reduced pressure

ORD-Eintrag

ord-8065a6b09371422cb15cd91b6fa97fb6

Quelldatensatz

uspto-grants-2007_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07285136B2