Water → N-isoamyl-N-(6-acetoxy naphthalene-2-sulfonyl)-D-valine tert-butyl ester

Participants

Reaction Steps

To a solution of N-(6-acetoxy naphthalene-2-sulfonyl)-D-valine tert-butyl ester (3.15 g, 7.48 mmol) in N,N-dimethylformamide (15 mL) is added potassium carbonate (3.09 g, 22.36 mmol), followed by 1-bromo-3-methyl butane (1.79 mL, 14.94 mmol), and the reaction is allowed to stir at ambient temperature for 16 h. Another equivalent of 1-bromo-3-methyl butane (0.9 mL, 7.5 mmol) is added and the reaction is allowed to stir for 16 h at ambient temperature. The reaction is poured over water and extracted three times with dichloromethane. The combined organic extracts are washed with brine, dried over magnesium sulfate and concentrated in vacuo. The crude product is purified by column chromatography and eluted with a gradient of 2-7% (hexanes-ethyl acetate) to afford the title compound as a yellow oil (2.5 g, 68% yield), along with N-isoamyl-N-(6-(3-methylbutoxy)naphthalene-2-sulfonyl)-D-valine tert-butyl ester as a yellow oil (0.3 g, 7.7% yield). LCMS (m/z): (492.26; M+1).

Provenance & Evidence