Triethylamine → 2-acetylsulfanylmethyl-3-(6-[N,N-bis(tert-butoxycarbonyl)amino]-5-methyl-pyridin-3-yl)-propionic acid ethyl ester

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Reaction Steps

Triethylamine (0.279 mL, 2.0 mmol) was added to a solution of 2-(6-[N,N-bis(tert-butoxycarbonyl)amino]-4-methyl-pyridin-3-ylmethyl)-acrylic acid ethyl ester (0.8 g, 1.9 mmol) in thioacetic acid (3 mL) at 0° C. The mixture was stirred at room temperature for 16 h. Ethyl acetate was added and the organic phase was washed with water, saturated NaHCO3 and brine and dried. The crude product was purified by flash chromatography (toluene/ethyl acetate, 3:1→1:2) to give pure 2-acetylsulfanylmethyl-3-(6-[N,N-bis(tert-butoxycarbonyl)amino]-5-methyl-pyridin-3-yl)-propionic acid ethyl ester (200 mg, 21%) and slightly impure 2-acetylsulfanylmethyl-3-(6-[N,N-bis(tert-butoxycarbonyl)amino]-4-methyl-pyridin-3-yl)-propionic acid ethyl ester (0.68 g).

Provenance & Evidence