Cesium carbonate → 1-(2,2-dimethoxyethyl)-4-nitro-1H-pyrazole

Temperature

85 °C

To a solution of 4-nitro-1H-pyrazole (1.50 g, 13.27 mmol) in MeCN (30 mL), 2-bromo-1,1-dimethoxyethane (2.34 mL, 19.90 mmol) and Cs2CO3 (6.48 g, 19.90 mmol) was added. The resulting mixture was refluxed (85° C.) for 20 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 partitioned between water and DCM, then the aq. layer was extracted with DCM (2×) and the comb. org. layers were dried (MgSO4), filtered and the solvent was removed under reduced pressure to yield 1-(2,2-dimethoxyethyl)-4-nitro-1H-pyrazole as a yellow oil which was used in the next step without further purification. LC-MS conditions B: tR=0.50 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. customThe residue was partitioned between water and DCM
6. extractionthe aq. layer was extracted with DCM (2×)
7. dry with materiallayers were dried (MgSO4)
8. filtrationfiltered
9. customthe solvent was removed under reduced pressure

ORD record

ord-288372e2f6f241cca6cab93fb2024e42

Source dataset

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09303023B2