3-Aminopyridine → 3-[1-(N-cyclopentylglycyl)-3,3-dimethyl-2,3-dihydro-1H-indol-6-yl]-5,5-dimethyl-1-{[2-(pyridin-3-ylamino)pyridin-4-yl]methyl}imidazolidine-2,4-dione

Participants

Reaction Steps

To a solution of 0.312 g of tert-butyl [2-(6-{3-[(2-chloropyridin-4-yl)methyl]-4,4-dimethyl-2,5-dioxoimidazolidin-1-yl}-3,3-dimethyl-2,3-dihydro-1H-indol-1-yl)-2-oxoethyl]cyclopentylcarbamate obtained in stage 1) of Example 3 in 12 mL of dioxane are successively added, under argon, 0.094 g of 3-aminopyridine, 0.028 g of (9,9-dimethyl-9H-xanthene-3,6-diyl)bis(diphenylphosphine) (Xantphos), 0.022 g of palladium acetate and 0.65 g of caesium carbonate. The reaction mixture is refluxed for 4 hours and then filtered, and the filtrate is concentrated under reduced pressure. The residue is taken up in 10 mL of dioxane, 12 mL of a 4N solution of hydrogen chloride in dioxane are then added and the reaction mixture is stirred at room temperature for 15 hours. After concentrating under reduced pressure, the residue is taken up in 40 mL of water, neutralized by addition of sodium hydrogen carbonate and extracted with three times 25 mL of dichloromethane. The combined organic phases are then washed with water, dried over magnesium sulphate filtered and concentrated under reduced pressure. The residue is triturated with diethyl ether and the solid obtained is filtered off and dried to give 0.12 g of 3-[1-(N-cyclopentylglycyl)-3,3-dimethyl-2,3-dihydro-1H-indol-6-yl]-5,5-dimethyl-1-{[2-(pyridin-3-ylamino)pyridin-4-yl]methyl}imidazolidine-2,4-dione, the characteristics of which are as follows:

Provenance & Evidence