Cesium carbonate → 2-(4-Nitro-1H-pyrazol-1-yl)ethan-1-ol

Temperatur

80 °C

To a solution of 4-nitro-1H-pyrazole (6.09 g, 52.20 mmol) in MeCN (80 mL), Cs2CO3 (18.71 g, 57.42 mmol) and 2-bromoethanol (4.59 mL, 62.64 mmol) was added. The resulting mixture was refluxed (80° C.) for 3.5 h, then the reaction mixture was allowed to reach rt. The mixture was diluted with DCM, filtered, the filter cake was washed with DCM and the filtrate was concentrated in vacuo. The residue was partitionned between water and EtOAc, the org. layer was separated and the aq. layer was extracted with EtOAc (1×). The combined org. layers were washed with brine, dried (MgSO4), filtered and concentrated in vacuo. Purification was performed by FC (EtOAc/hept 7:3 to EtOAc/MeOH 9:1) to obtain 2-(4-nitro-1H-pyrazol-1-yl)ethanol as a white solid. LC-MS conditions A: tR=0.44 min, [M+H]+=no ionization.

1. customto reach rt
2. filtrationfiltered
3. washthe filter cake was washed with DCM
4. concentrationthe filtrate was concentrated in vacuo
5. customlayer was separated
6. extractionthe aq. layer was extracted with EtOAc (1×)
7. washlayers were washed with brine
8. dry with materialdried (MgSO4)
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customPurification

ORD-Eintrag

ord-e3d3a52ddae944b59cab4a785d789545

Quelldatensatz

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09303023B2