反应详情

温度

60 °C

At 0-5° C., 56.0 g (0.43 mol) of 2-amidino-acetic acid ethyl ester [for preparation see: Liebigs Ann. Chem., 1561 (1981)] are introduced into 172 ml of DMPU. 56.0 ml (0.45 mol) of bromopyruvic acid ethyl ester are added dropwise thereto within the course of 30 min and the reaction mixture is then heated at 60° C. for 3 hours. The dark-brown reaction solution is poured into 1 liter of ice-water and extracted with 1 liter of ethyl acetate and twice with a 0.5 liter of ethyl acetate each time. The organic phases are washed three times with a 0.5 liter of water and a 0.5 liter of brine, dried (Na2SO4) and concentrated by evaporation. Column chromatography (SiO2, hexane/ethyl acetate [1:1]) and crystallization from diethyl ether/hexane yield the title compound; m.p. 147-149° C.; MS: (M)+ =226.

1. extractionextracted with 1 liter of ethyl acetate and twice with a 0.5 liter of ethyl acetate each time
2. washThe organic phases are washed three times with a 0.5 liter of water
3. dry with materiala 0.5 liter of brine, dried (Na2SO4)
4. concentrationconcentrated by evaporation
5. customColumn chromatography (SiO2, hexane/ethyl acetate [1:1]) and crystallization from diethyl ether/hexane