Imidazole → (S)-3-[tert-butyldimethylsilyloxy]glutaric acid monoamide

Participants

Reaction Conditions

Reaction Steps

(S)-Benzyl-3-hydroxyglutaramate (100 g) was dissolved in dimethyl formamide. To this Imidazole (35 g) was added and the solution was cooled to 5° C. To this a solution of tert-butyldimethylsilylchloride (68.5 g) dissolved in dimethyl formamide (250 ml) was added under cooling. The mixture was warmed to 20-25° C. and stirred. The reaction mixture was cooled and quenched with water. To the reaction mixture ethyl acetate and water was added and stirred. The layers were separated and the organic phase was washed thrice with water. To the organic phase Palladium on charcoal (5%, 1 g) was added and stirred under hydrogen atmosphere (˜2.8 Kg). Palladium was removed by filtration. The filtrate was mixed with water and adjusted pH to ˜9.0 by using Aq ammonia solution. The reaction mass was stirred and layers were separated. The aqueous phase was washed with dichloromethane and dichloromethane was added to aqueous phase. The reaction mass was cooled to 5° C. and pH was adjusted to 4.0 with Aq phosphoric acid. The reaction mass was stirred and layers were separated. The organic phase was washed with water and dried over sodium sulphate. The organic layer was evaporated under vacuum to yield residue. Residue was dissolved in dichloromethane and to this solution heptane was added, stirred, filtered and dried to yield (S)-3-(tert-butyl dimethylsilyloxy)glutaric acid monoamide.

Provenance & Evidence