Dimethylformamide → 5-methyl-1-(tetrahydro-2H-pyran-2-yl)-3-(trifluoromethyl)-1H-pyrazole-4-carbaldehyde

Temperature

-78 °C

A solution of 4-bromo-5-methyl-1-(tetrahydro-2H-pyran-2-yl)-3-(trifluoromethyl)-1H-pyrazole (1.17 g, 3.74 mmol) in THF (13 mL) was cooled to −78° C., then n-BuLi (1.6 M in hexane, 3.7 mL, 6.0 mmol) was added dropwise. The reaction was held at −78° C. for 10 minutes, then DMF (580 μL, 7.5 mmol) was added and the reaction was stirred at −78° C. for 1.5 h. The reaction was quenched at −78° C. by addition of sat'd NH4Cl and ether, the phases were separated and the aqueous phase was washed with ether. The combined organic phase was washed with water, then sat'd NaCl, dried over MgSO4 and reduced to dryness in vacuo to give the crude product, which was used without further purification (1.04 g). 1H NMR (400 MHz, CDCl3): δ 10.0 (s, 1H), 5.41 (m, 1H), 4.00 (m, 1H), 3.66 (m, 1H), 2.68 (s, 3H), 2.41 (m, 1H), 2.17 (m, 1H), 2.00 (m, 1H), 1.69 (m, 3H).

1. customThe reaction was quenched at −78° C. by addition of sat'd NH4Cl and ether
2. customthe phases were separated
3. washthe aqueous phase was washed with ether
4. washThe combined organic phase was washed with water
5. dry with materialdried over MgSO4

ORD record

ord-b4efc57bd7244743a4c1b1b2f454b2eb

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08563541B2