Diisopropylamine → 4-Pyridyl-t-butydimethylsilyloxymethyl 4-t-butylphenyl ketone

Participants

Reaction Conditions

Reaction Steps

To a cooled solution of diisopropylamine (183 mg, 1.81 mmol) in dry THF (0.35 mL) at -20° C. was added a solution of n-butyllithium in hexanes (0.83 mL of a 2.5M solution, 2.08 mmol). Stirred at -20° C. for 1 hr and then added a solution of 4-pyridyl-t-butydimethylsilyloxymethyl 4-fluorophenyl ketone from Step B (383 mg, 1.72 mmol) in THF (0.45 mL). Stirred at -20° C. for 45 min, resulting in a thick yellow-brown solution. A solution of 4-t-butyl-N-methoxy-N-methyl-benzamide (400 mg, 1.81 mmol) in THF (0.5 mL) was added and the solution stirred at -20° to 0° C. for 5 h. The reaction was cooled to -20° C. and quenched by the addition of a saturated ammonium chloride solution. The reaction mixture was then extracted with ethyl acetate (3 times) and the combined extracts washed successively with water (2 times) and saturated salt solution and dried over anhydrous sodium sulfate. The mixture was filtered and the solvent removed by rotoevaporation. The residue was purified by flash column chromatography on silica gel eluted with 5-10% ethyl acetate in hexanes to yield the title compound as a yellow oil (341 mg, 49% yield).

Provenance & Evidence