Dimethylformamide → 4-Methoxy-1-(2-trimethylsilanyl-ethoxymethyl)-indazole-5-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 5-bromo-4-methoxy-1-(2-trimethylsilanyl-ethoxymethyl)-indazole (179 mg, 0.50 mmol) in THF (5.0 mL) at −78° C. under a nitrogen atmosphere was added n-butyl lithium (2.5 M in hexanes, 220 μL, 0.55 mmol) dropwise. The mixture was stirred at −78° C. for 1 hour and then DMF (78 μL, 1.0 mmol) was added. The mixture was stirred at −78° C. for 30 min, then allowed to reach RT and stirred for a further 1 hour. The reaction mixture was quenched with water (5 mL), separated and extracted with ethyl acetate (2×20 mL). The combined organic layers were washed with brine (20 mL), dried (Na2SO4), filtered and concentrated in vacuo. The resulting residue was subjected to flash chromatography (SiO2, 20% ethyl acetate in cyclohexane) to give the title compound as a yellow oil (78 mg, 51%). LCMS (Method B): RT=4.55 min, [M+H]+=307.

Provenance & Evidence