Dimethylformamide → 1-[2-methyl-2-((R)-1-oxiranylmethoxy)-propyl]-3-nitro-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-methyl-1-(3-nitro-pyrazol-1-yl)-propan-2-ol (1.31 g, 7.07 mmol), and DMF (60 mL) was stirred at 0° C. for 5 min, then NaH (60% dispersion in oil, 0.85 g, 21.2 mmol) was added and stirred 20 min at 0° C. R-(−)-glycidyl-3-nitrobenzenesulfonate (2.75 g, 10.6 mmol) was added and stirred at 0° C. for 1 h then warmed to rt for 14 h. The mixture was then diluted with NH4Cl(s), ethyl acetate, the organic phase was separated, washed with NaHCO3(satd) dried with Na2SO4, and filtered. The mixture was then concentrated and purified by column chromatography (40-240 g Analogix column, 70% EtoAc/heptane to yield the product 1-[2-methyl-2-((R)-1-oxiranylmethoxy)-propyl]-3-nitro-1H-pyrazole as a white solid (0.7 g, 41%).

Provenance & Evidence