反应详情

A solution of 505 mg (3.19 mmol) of 2-(N,N-dimethylamino)-4(hydroxymethyl)thiazole, 3.19 mmol of α-isocyanato-L-valine methyl ester, and 100 mg of 4-dimethylaminopyridine in 30 ml of dichloromethane was heated at reflux for 3 h. The resulting solution was allowed to cool, diluted with dichloromethane, washed sequentially with 10% citric acid, aqueous Na2CO3, and brine, dried over Na2SO4, and concentrated in vacuo. The residue was purified by silica gel chromatography using 2% methanol in chloroform to provide 0.95 g (95%) of the desired compound, Rf 0.42 (4% methanol in chloroform). 1H NMR (CDCl3) δ 0.84 (d, J=7 Hz, 3 H), 0.93 (d, J=7 Hz, 3 H), 2.12 (m, 1 H), 3.11 (s, 6 H), 3.73 (s, 3 H), 4.24 (dd, J=8, 4 Hz, 1 H), 4.99 (s, 2 H), 5.26 (br d, 1 H), 6.49 (s, 1 H). Mass spectrum: (M+H)+ =316.

1. temperatureat reflux for 3 h
2. temperatureto cool
3. washwashed sequentially with 10% citric acid, aqueous Na2CO3, and brine
4. dry with materialdried over Na2SO4
5. concentrationconcentrated in vacuo
6. customThe residue was purified by silica gel chromatography