Methyl iodide → HCID 66833759, compound

Participants

Reaction Steps

A solution of ethyl 2-(tert-butoxycarbonylamino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate (104 mg, 0.27 mmol) in THF (2.7 mL) was cooled to 0° C. and treated with methyl iodide (0.084 mL, 1.35 mmol) and NaHMDS (0.41 mL, 1 M solution in THF, 0.41 mmol). After stirring for 16 h at room temperature, additional methyl iodide (0.042 mL, 0.77 mmol) was added and the mixture was warmed to 35° C. for 6 hours. The reaction was quenched with saturated NH4Cl solution (2 mL), diluted with ethyl acetate, washed with saturated aqueous sodium bicarbonate solution, sat'd aq sodium chloride, dried over MgSO4 and concentrated. Purification by column chromatography (5-40% ethyl acetate in heptane) gave ethyl 2-(tert-butoxycarbonyl(methyl)amino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate (59 mg, 55%). Rf 0.34 (20% ethyl acetate in heptane). 1H NMR (CDCl3, 300 MHz) δ 4.72-4.68, 4.43-4.38 (m, 1H, rotamers), 4.15 (q, J=7.3 Hz, 2H), 2.81, 2.77 (s, 3H, rotamers), 1.87-1.61 (m, 2H), 1.53-1.23 (m, 28H), 0.78 (t, J=7.3 Hz, 2H). ESI MS found for C20H38B1N1O6 m/z [400.5 (M+1)].

Provenance & Evidence