反应详情

Diethyl axodicarboxylate (1.39 g, 8 mmol) in THF (5 mL, was added dropwise to a stirred solution of methyl 9-hydroxynonanoate (1.50 g, 8 mmol), 3,4-diphenylimidazolidine-2,5-dione (2.02 g, 8 mmol) obtained according to the procedure of K. C. Joshi, et al., J. Het. Chem., 18, 1651-1653 (1981) and triphenylphosphine (2.10 g, 8 mmol) in THF (35 mL). The mixture was stirred at room temperature for 72 hours, the THF removed in vacuo and the residue triturated with a mixture of hexanes and diethyl ether. The mixture was filtered, the filtrate concentrated and subjected to chromatography on a column of silica gel using a mixture of hexanes and ethyl acetate (3:2) as eluent. Elution gave methyl 2,5-dioxo-3,4-diphenyl-1-imidazolidinenonanoate (2.78 g, 82%), mp 69°-72° C.

1. customobtained
2. customthe THF removed in vacuo
3. customthe residue triturated with a mixture of hexanes and diethyl ether
4. filtrationThe mixture was filtered
5. concentrationthe filtrate concentrated
6. additiona mixture of hexanes and ethyl acetate (3:2) as eluent
7. washElution