N,N,N',N'-Tetramethylethylenediamine → 2-cyclopentyl-1-(3,4-dichloro-phenyl)-1-[1-(2-trimethylsilanyl-ethoxymethyl)-1H-pyrrolo[2,3-b]pyridin-2-yl]-ethanol

Participants

Reaction Steps

A solution of n-butyl lithium in hexane (2.5 M, 4.5 mL, 11.2 mmol) was treated with N,N,N′,N′-tetramethylethylenediamine (1.69 mL, 11.2 mmol) dropwise, which resulted in a slight exotherm. The resulting yellow mixture was then stirred at room temperature for 15 min. After this time, the mixture was treated with 1-(2-trimethylsilanyl-ethoxymethyl)-1H-pyrrolo[2,3-b]pyridine (prepared as in Example 138, 3.48 g, 14.0 mmol) dropwise. The resulting mixture was then stirred at room temperature for 30 min and then treated with a solution of 2-cyclopentyl-1-(3,4-dichloro-phenyl)-ethanone (1.8 g, 7.0 mmol) in tetrahydrofuran (8 mL) and then stirred at room temperature for 6 h. After this time, the reaction mixture was quenched by the addition of a saturated aqueous ammonium chloride solution (25 mL) and it was then stirred over the weekend. The reaction mixture was then extracted with ethyl acetate (2×100 mL) and the combined organic layers were then dried over magnesium sulfate, filtered and the filterate concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 10% ethyl acetate/hexanes) afforded 2-cyclopentyl-1-(3,4-dichloro-phenyl)-1-[1-(2-trimethylsilanyl-ethoxymethyl)-1H-pyrrolo[2,3-b]pyridin-2-yl]-ethanol (1.13 g, 32%) as a yellow oil.

Provenance & Evidence