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

Participants

Reaction Conditions

Reaction Steps

A solution of 4-bromo-3-(difluoromethyl)-5-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole (0.60 g, 2.0 mmol) in tetrahydrofuran (7.00 mL, 86.3 mmol) was cooled at −78° C. Into the reaction was added 1.6 M of n-butyllithium in hexane (2.00 mL) and was stirred at −78° C. for 5 min. N,N-Dimethylformamide (0.31 mL, 4.1 mmol) was added and stirred at −78° C. for 1 h. The reaction was extracted with ethyl acetate and the organic extracts were washed with water, saturated NaCl, dried (MgSO4) and concentrated in vacuo. The crude product was used in the next reaction without further purification. 1H NMR (CDCl3): δ 10.12 (s, 1H), 6.81-6.95 (t, 1H), 5.38 (m, 1H), 4.03 (m, 1H), 3.68 (m, 1H), 2.66 (s, 3H), 2.42 (m, 1H), 2.14 (m, 1H), 1.96 (m, 1H), 1.50-1.75 (m, 3H).

Provenance & Evidence