反应详情

温度

-78 °C

Dissolve dimethylsulfoxide (0.324 mL, 4.56 mmol) in DCM (10 mL) and cool the solution to −78° C. Add oxalyl chloride (0.239 mL, 2.74 mmol) to the mixture dropwise and stir at −78° C. for 20 min. Add (3,5-dimethyl-1-pyridin-2-yl-1H-pyrazol-4-yl)-methanol (0.369 g, 1.82 mmol) in DCM (10 mL) and stir the mixture at −78° C. for 1 hr. Add triethylamine (1.27 mL, 9.12 mmol) to the mixture and warm to room temperature then stir for 18 hr. Add saturated aqueous sodium bicarbonate and extract the aqueous 3 times with DCM, dry organic solution then filter and concentrate. Purify using silica gel chromatography, eluting with 20:80 hexanes:ethyl acetate to give 3,5-dimethyl-1-pyridin-2-yl-1H-pyrazole-4-carbaldehyde as a yellow solid (0.358 g, 97%). MS (m/z): 202 (M+1).

1. extractionAdd saturated aqueous sodium bicarbonate and extract the aqueous 3 times with DCM, dry organic solution
2. filtrationthen filter
3. concentrationconcentrate
4. customPurify
5. washeluting with 20:80 hexanes