Dimethyl Sulfoxide → 1-methyl-3-(trifluoromethyl)-1H-pyrazole-4-carbaldehyde

Temperature

-78 °C

Dissolve (1-methyl-3-trifluoromethyl-1H-pyrazol-4-yl)-methanol (1.41 g, 7.83 mmol) in DCM (25 mL) and dimethylsulfoxide (2.22 mL, 31.3 mmol) and cool to −78° C. Add oxalyl chloride (1.91 mL, 21.9 mmol) dropwise over 15 min. and stir at −78° C. for an additional 1 hr. Add triethylamine (6.55 mL, 47.0 mmol) dropwise and stir another 1 hr. Quench with water (20 mL) and dilute with DCM (50 mL) and warm to room temperature for 1 hr. Separate the organic layer; dry (sodium sulfate), filter, concentrate and purify (silica gel chromatography, eluting with 80:20 hexanes:ethyl acetate), to give the title preparation (0.98 g, 71%). 1H-NMR (400 MHz, CDCl3) δ 9.94 (s, 1H), 7.97 (s, 1H), 3.99 (s, 3H).

1. customQuench with water (20 mL)
2. additiondilute with DCM (50 mL)
3. temperaturewarm to room temperature for 1 hr
4. customSeparate the organic layer
5. dry with materialdry (sodium sulfate)
6. filtrationfilter
7. concentrationconcentrate
8. custompurify
9. wash(silica gel chromatography, eluting with 80:20 hexanes:ethyl acetate)
10. customto give the title
11. custompreparation (0.98 g, 71%)

ORD record

ord-2925f8cc3ef44929bb764946bc2bebc4

Source dataset

uspto-grants-2012_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08202873B2