反应详情

Under an argon atmosphere, 1.65 g (1 0 mmol) of 2-amidino-acetic acid ethyl ester hydrochloride (for preparation see: Liebigs Ann. Chem., 1895 (1977)) are introduced into 10 ml of ethanol and, at 0-5° C., 0.73 g (10 mmol) of sodium ethanolate is added thereto. The bright yellow suspension is stirred for 20 min and then 1.4 g (5 mmol) of 2-bromo-1-(biphen-4-yl)-ethan-1-one (2-bromo-4'-phenyl-acetophenone; Aldrich; Milwaukee/USA) are added thereto. After 48 hours' stirring at RT, the reaction mixture is concentrated by evaporation and the residue is taken up in ethyl acetate and washed with 3 portions of water and brine. The aqueous phases are extracted twice with ethyl acetate and the organic phases are dried over MgSO4 and concentrated by evaporation. Column chromatography (SiO2 ; ethyl acetate/hexane [1:1]) and stirring in diisopropyl ether/hexane yield the title compound; m.p. 186-188° C.; TLC-Rf =0.17 (ethyl acetate/hexane [1:1]); FAB-MS: (M+H)+ =306.

1. stirringAfter 48 hours' stirring at RT
2. concentrationthe reaction mixture is concentrated by evaporation
3. washwashed with 3 portions of water and brine
4. extractionThe aqueous phases are extracted twice with ethyl acetate
5. dry with materialthe organic phases are dried over MgSO4
6. concentrationconcentrated by evaporation
7. stirringColumn chromatography (SiO2 ; ethyl acetate/hexane [1:1]) and stirring in diisopropyl ether/hexane