p-Toluenesulfonic acid → HCID 178427578, compound

Participants

Reaction Conditions

Reaction Steps

In 500 ml of tetrahydrofuran is dissolved 46.2 g (100 millimoles) of Z-Arg(Tos)-OH, and 11 ml of N-methylmorpholine is added to the solution and the mixture is stirred at -5° C. for 5 minutes. Then, 9.6 ml of ethyl chloroformate is added to the mixture, and a cooled solution of 39.4 g (100 millimoles) of Tos-OH.H-Leu-OBzl and 11 ml of N-methylmorpholine in dimethylformamide is added to the above mixture. The resulting mixture is stirred at -5° to 0° C. for 4 hours and concentrated under reduced pressure. The residue is dissolved in 700 ml of ethyl acetate, and the solution is washed with 0.1 N aqueous hydrochloric acid, 1 N aqueous NaHCO3 and water and concentrated under reduced pressure. Ether is added to the residue and the formed precipitate is recovered by filtration to obtain 58 g of intended Z-Arg(Tos)-Leu-OBzl (the yield being 87%).

Provenance & Evidence