反应详情

温度

80 °C

A magnesium maleate solution was prepared by dissolving 29.4 g (0.3 mol) of maleic anhydride in 50 ml of water and by adding to the reaction mixture 35.0 g of magnesium hydroxide (0.3 mol Mg(OH)2) slurried in 70 ml of water. During the adding the temperature of the reaction mixture was maintained at 70-90° C. 17 g (0.05 mol) of lanthanum(III) nitrate, La(NO3)3×6 H2O was added to the reaction mixture together with diethanolamine (10.5 g, 0.1 mol). The pH of the reaction mixture was adjusted to a pH value of 11 by an addition of a 48% sodium hydroxide solution. The reaction mixture was stirred at 85° C. under a reflux condenser for 10 hours. The reaction mixture was cooled and was rendered acidic (pH 1.8) by means of a concentrated sulfuric acid. Thereafter the reaction mixture was reheated to 60° C., and 10 g of oxalic acid and 50 ml of water were added, the mixture was stirred at 60° C. for 20 minutes, and the formed precipitate was removed from the hot solution by filtration. The filtrate was cooled and any precipitate subsequently formed was removed by filtration. The remaining solution (42 ml), which contained 54% water, was analyzed for organic compounds by means of 13C NMR spectra and mass spectrometer as silyl or methyl ester derivatives.

1. temperatureThe reaction mixture was cooled
2. customwas reheated to 60° C.
3. stirringthe mixture was stirred at 60° C. for 20 minutes
4. customthe formed precipitate was removed from the hot solution by filtration
5. temperatureThe filtrate was cooled
6. customany precipitate subsequently formed
7. customwas removed by filtration