反应详情

温度

90 °C

A solution of 3-nitro-1H-pyrazole (Intermediate 2, 12.0 g, 106 mmol) in N,N-dimethylformamide (150 mL) was treated with para-toluenesulfonic acid (S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl ester (25.5 g, 89.0 mmol), and potassium carbonate (24.5 g, 178 mmol). The reaction mixture was heated to 90° C. for 6 h under nitrogen. After this time, the reaction mixture was diluted with ethyl acetate, washed with water and a saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, rinsed and concentrated in vacuo. Silica gel column chromatography (ISCO 120 g, 5-30% ethyl acetate/hexanes) afforded 1-((R)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-3-nitro-1H-pyrazole (14.5 g, 73%) as a light yellow oil; ESI-LRMS m/e calcd for C9H13N3O4 [M+H+] 228, found 228 [M+H+].

1. washwashed with water
2. dry with materiala saturated aqueous sodium chloride solution, dried over sodium sulfate
3. filtrationfiltered
4. washrinsed
5. concentrationconcentrated in vacuo