[CH2:1]([CH2:3][NH2:4])[OH:2].COC(N1[C:13](=[O:14])[CH:12]=[CH:11][C:10]1=[O:15])=O.S(=O)(=O)(O)O>C(=O)(O)[O-].[Na+]>[OH:2][CH2:1][CH2:3][N:4]1[C:13](=[O:14])[CH:12]=[CH:11][C:10]1=[O:15]As shown in FIG. 1, to a solution of ethanolamine (1.8 g, 29.5 mmol) in saturated sodium bicarbonate solution (100 ml) was added N-methoxycarbonylmaleimide (95 g, 32.3 mmol) in portions with vigorous stirring at 0° C. The mixture was allowed to warm to room temperature and stirred for 1 hour. The pH of the mixture was adjusted to 6-7 by careful addition of concentrated sulfuric acid (5 ml). The resultant solution was freeze dried and the solid residue extracted with ethyl acetate (2×400 ml) by stirring for 30 min. with each extraction. The ethyl acetate extracts were collected by filtration and evaporated in vacuo to afford N-(2-hydroxyethyl)maleimide (formula I) as a white solid (4.0 g, 96% yield); thin layer chromatography (TLC), Rf=0.27, ethyl acetate/petroleum ether 1:1.
불러오는 중…
