Cesium carbonate → 1-(3,3-dimethoxypropyl)-4-nitro-1H-pyrazole

Temperature

80 °C

To a solution of 4-nitro-1H-pyrazole (4.50 g, 39.80 mmol) in MeCN (135 mL), 3-bromo-1,1-dimethoxypropane (7.25 mL, 47.76 mmol) and Cs2CO3 (16.30 g, 50.0 mmol) was added. The resulting mixture was refluxed (80° C.) for 1.5 h and allowed to reach rt overnight. 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 brine and EtOAc, then the org. layer was separated and the aq. layer was extracted with EtOAc (2×). The comb. org. layers were dried (MgSO4), filtered and the solvent was removed under reduced pressure to yield 1-(3,3-dimethoxypropyl)-4-nitro-1H-pyrazole as a yellow oil which was used in the next step without further purification. LC-MS conditions B: tR=0.54 min, [M+H]+=no ionization.

1. filtrationfiltered
2. washthe filter cake was washed with DCM
3. concentrationthe filtrate was concentrated in vacuo
4. customThe residue was partitioned between brine and EtOAc
5. customlayer was separated
6. extractionthe aq. layer was extracted with EtOAc (2×)
7. dry with materiallayers were dried (MgSO4)
8. filtrationfiltered
9. customthe solvent was removed under reduced pressure

ORD record

ord-d55ca8deae304dbba83dd5da21b1e026

Source dataset

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09303023B2