反应详情

A solution of 7.0 g (0.25 mol) of 2-phthalimidoethyl acetoacetate and 3.1 g (0.025 mol) of methyl3-aminocrotonate in 150 ml of 2-propanol was refluxed for 15 hours under nitrogen. The solvent was removed in vacuo and the residue was subjected to flash chromatography (silica gel, 1:1 petroleum ether/ethyl acetate). The isolated product was recrystallized in dichloromethane/hexane to give 3.5 g (50%) of a pale yellow solid; m.p. 188°-190° C. NMR: (CDCl3) δ 2.1 (9H,d), 3.5 (3M,s), 3.7 (2H,m), 4.2 (2H,m), 4.6 (1H,s), 5.8 (1H,s), 7.2 (8H,m).

1. customThe solvent was removed in vacuo
2. customThe isolated product was recrystallized in dichloromethane/hexane