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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence