4-Methylmorpholine → Benzyl (tert-butoxycarbonyl)glycylglycinate

Participants

Reaction Steps

14.2 g (42 mmoles) of glycine benzyl ester p-toluenesulfonate are dissolved in 100 ml of dimethyl formamide, 4.6 ml (42 mmoles) of N-methylmorpholine and 14.2 g (40 mmoles) of tert.-butoxycarbonyl-glycine 2,4,5-trichlorophenyl ester are added, and the mixture is stirred at room temperature overnight. The reaction mixture is evaporated, and the residue is dissolved in a mixture of 150 ml of ethyl acetate and 50 ml of water. The ethyl acetate phase is washed twice with 30 ml of ice-cooled 1 n aqueous hydrochloric acid, each, and then with water, dried over sodium sulfate and evaporated. The residue is triturated with a 1:1 mixture of diisopropyl ether and petroleum ether, filtered, the solid is washed with the same solvent mixture and dried in a desiccator. 11.0 g (82.8%) of tert.-butoxycarbonyl-glycyl-glycine benzyl ester are obtained; m.p.: 83° C., Rf14 =0.1-0.2.

Provenance & Evidence