2-(N,N-Diethylamino)-4-(hydroxymethyl)thiazole → N-((2-(N,N-Diethylamino)-4-thiazolyl)methoxycarbonyl)valine Methyl Ester

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Reaktionsschritte

A solution of 5.11 mmol of α-isocyanato-valine methyl ester in 10 ml of dichloromethane was treated with 0.864 g (4.65 mmol) of 2-(N,N-diethylamino)-4-(hydroxymethyl)thiazole and 0.46 mmol of 4-dimethylaminopyridine. The resulting solution was stirred at ambient temperature for 16 h, after which it was diluted with 200 ml of chloroform, washed successively with 10% citric acid, aqueous NaHCO3, and saturated brine. After drying over Na2SO4, the solvent was removed in vacuo, and the residue was chromatographed on silica gel using 1-2% methanol in chloroform to provide 1.31 g (82%) of the desired compound, Rf 0.51 (4% methanol in chloroform) as an oil. 1H NMR (CDCl3) δ0.89 (d, J=7 Hz, 3H), 0.96 (d, J=7 Hz, 3H), 1.24 (t, J=7 Hz, 6H), 2.15 (m, 1H), 3.51 (q, J=7 Hz, 4H), 3.74 (s, 3H), 4.29 (dd, J=8, 4 Hz, 1H), 5.03 (s, 2H), 5.34 (br d, J=8 Hz, 1H), 6.42 (s, 1H). Mass spectrum: (M+H)+ =344.

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