Potassium Carbonate → (S)-3-(3-nitro-1h-pyrazol-1-yl)propane-1,2-diol

Temperature

120 °C

A solution of 3-nitro-1H-pyrazole (Intermediate 2, 205 mg, 1.81 mmol) in anhydrous N,N-dimethylformamide (3.5 mL) was treated with (R)-glycidol (148 mg, 2.00 mmol) and potassium carbonate (770 mg, 5.58 mmol). The mixture was heated in a sealed vial at 120° C. for 1 h. After this time, the mixture was diluted with water (15 mL) and extracted with ethyl acetate (6×25 mL). The combined organic layers were washed with a saturated aqueous sodium chloride solution (15 mL), dried over magnesium sulfate, filtered and concentrated in vacuo. Silica gel column chromatography (Teledyne Isco RediSep Flash Column 40 g, 15-100% ethyl acetate/hexanes) afforded (S)-3-(3-nitro-pyrazol-1-yl)-propane-1,2-diol (118 mg, 34%) as a thick yellow oil. 1H-NMR (400 MHz, CD3OD) δ 3.55 (2H, d, J=5.2 Hz), 4.02-4.05 (1H, m), 4.20 (1H, dd, J=13.6 Hz, 7.6 Hz), 4.39 (1H, dd, J=14.0 Hz, 3.6 Hz), 6.92 (1H, d, J=2.0 Hz), 7.79 (1H, d, J=2.0 Hz).

1. extractionextracted with ethyl acetate (6×25 mL)
2. washThe combined organic layers were washed with a saturated aqueous sodium chloride solution (15 mL)
3. dry with materialdried over magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo

ORD record

ord-c2dc1bab799942e2b8c098e78c988e86

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08258134B2