p-Toluenesulfonic acid monohydrate → 1-((S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-3-nitro-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

A solution of (S)-3-(3-nitro-pyrazol-1-yl)-propane-1,2-diol (1 g, 5.34 mmol) in 2,2-dimethoxypropane (8.5 mL, 0.63M) and tetrahydrofuran (10 mL, 0.53 M) was treated with para-toluenesulfonic acid monohydrate (0.11 g, 0.57 mmol). The reaction was stirred under nitrogen at 25° C. overnight. After this time, the reaction was concentrated in vacuo. Silica gel column chromatography (Aspire 40 g, 20-45% ethyl acetate/hexanes) afforded 1-((S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-3-nitro-1H-pyrazole (348.5 mg, 29%) as a viscous yellow/orange oil. The material was used without further purification.

Provenance & Evidence