Imidazole → 3-(1-Acetyl-3,3-dimethyl-2,3-dihydro-1H-indol-6-yl)-5,5-dimethyl-imidazolidine-2,4-dione

Participants

Reaction Conditions

Reaction Steps

A solution of 6.6 g of 1,1′-carbonylbis(1H-imidazole) and 460 mg of 1H-imidazole in 50 mL of tetrahydrofuran is stirred under argon and cooled in an ice bath at 0° C. To this solution is added a suspension of 6.9 g of 1-acetyl-3,3-dimethylindolin-6-amine obtained in stage f) below in 50 mL of tetrahydrofuran. After stirring for one hour, 9.5 mL of triethylamine and 5.2 g of methyl 2-methylalaninate hydrochloride are added and the mixture is stirred for two hours at room temperature and then refluxed for 17 hours. After cooling to room temperature, the mixture is diluted with 800 mL of water and the precipitate formed is filtered off, washed with four times 25 mL of water and with three times 15 mL of diethyl ether and then dried to give 8 g of 3-(1-acetyl-3,3-dimethyl-2,3-dihydro-1H-indol-6-yl)-5,5-dimethylimidazolidine-2,4-dione in the form of a beige-coloured solid, the characteristics of which are as follows:

Provenance & Evidence