Dimethylformamide → 4-[4-(2-Ethoxy-naphthalen-1-ylmethyl)-3,5-diethyl-pyrazol-1-yl]-3,5-dimethyl-benzaldehyde

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Reaction Steps

A solution of 1-(4-bromo-2,6-dimethylphenyl)4-(2-ethoxy-naphthalen-1-ylmethyl)-3,5-diethyl-1H-pyrazole (0.400 g, 0.81 mmol) in 2.0 ml anhydrous THF was added dropwise to a dry ice-acetone bath cooled solution of n-butyl lithium (2.5 M solution in hexane, 0.358 ml, 0.90 mmol). After stirring 10 minutes, anhydrous dimethylformamide (0.188 ml, 2.43 mmol) was added. After 30 minutes the cooling bath was removed and the mixture was stirred 1 hour. The reaction was quenched by addition of 0.25 ml of a saturated aqueous ammonium chloride solution. After stirring for 5 minutes, the reaction mixture was well-mixed with ethyl acetate/brine (20 ml of each). The aqueous phase was then twice extracted with equal-volume portions of fresh ethyl acetate. The combined organic extracts were dried over anhydrous sodium sulfate, and concentrated in vacuo to yield an oil (400 mg). Flash chromatography of the entire sample (silica gel, 40 micron mesh; elution with ethyl acetate/hexanes=1:4 in volume) afforded the title compound (100 mg) as an oil.

Provenance & Evidence