反应详情

温度

105 °C

To a solution of 3.5 g of 3-(4-tert-butylphenyl)-1-[(2-chloropyridin-4-yl)methyl]-5,5-dimethylimidazolidine-2,4-dione obtained in stage a) of Example 7 in 90 mL of dioxane are successively added, under argon, 406 mg of palladium diacetate, 1.1 g of (9,9-dimethyl-9H-xanthene-3,6-diyl)bis(diphenylphosphine)[xantphos], 12.9 g of caesium carbonate and 1.86 g of ethyl carbamate. The reaction mixture is heated at 105° C. for 7 hours, filtered and concentrated under reduced pressure. The residue is purified by chromatography on a column of silica, eluting with a mixture of cyclohexane and ethyl acetate (60/40 by volume) to give 1.8 g of ethyl (4-{[3-(4-tert-butylphenyl)-5,5-dimethyl-2,4-dioxo-imidazolidin-1-yl]methyl}pyridin-2-yl)carbamate, the characteristics of which are as follows:

1. filtrationfiltered
2. concentrationconcentrated under reduced pressure
3. customThe residue is purified by chromatography on a column of silica
4. washeluting with a mixture of cyclohexane and ethyl acetate (60/40 by volume)