反应详情

温度

-78 °C

Dissolve (3-isobutyl-5-methyl-1-pyridin-2-yl-1H-pyrazol-4-yl)-acetic acid ethyl ester (3.35 g, 11.11 mmol) in tetrahydrofuran (50 mL) and cool to −78° C. Add diisobutylaluminum hydride (33.3 mL, 33.3 mmol, 1 M in toluene) dropwise. Continue stirring at −78° C. for 6 hr. Quench with saturated aqueous potassium sodium tartrate solution (50 mL) and warm to room temperature over 16 hr. Extract with ethyl acetate (2×100 mL). Combine organic layers, dry (sodium sulfate), filter and concentrate. Purify using silica gel chromatography, eluting with 90:10 hexanes:ethyl acetate, to give the title preparation (1.60 g, 56%). 1H-NMR (400 MHz, CDCl3) δ 9.62 (t, 1H), 8.39 (m, 1H), 7.77 (m, 2H), 7.15 (m, 1H), 3.45 (d, 2H), 2.96 (d, 2H), 2.22 (s, 3H), 1.80 (m, 1H), 0.81 (d, 6H).

1. customQuench with saturated aqueous potassium sodium tartrate solution (50 mL)
2. temperaturewarm to room temperature over 16 hr
3. extractionExtract with ethyl acetate (2×100 mL)
4. dry with materialCombine organic layers, dry (sodium sulfate)
5. filtrationfilter
6. concentrationconcentrate
7. customPurify
8. washeluting with 90:10 hexanes
9. customethyl acetate, to give the title
10. custompreparation (1.60 g, 56%)