Hydrochloric Acid → HCID 178427536, compound

Participants

Reaction Steps

In a mixed liquid of 100 ml of acetic acid, 100 ml of 25% HBR-acetic acid and 3.4 g of anisole is dissolved 33.5 g (30.9 millimoles) of Z-Arg(Tos)-Leu-Leu-Gln-Gly-Leu-Val-NH2, and the solution is stirred at room temperature for 1.5 hours and is then added to 2.5 l of ether. The formed precipitate is recovered by decantation and dissolved in 300 ml of ethanol. The solution is added to ether and an HBr salt of the Z-compound is recovered by decantation. Then, the recovered salt (34.5 g, 30.9 millimoles) is dissolved in 400 ml of dimethylformamide, and 6.8 g of N-methylmorpholine is added to the solution under cooling. Then, 14 g (37 millimoles) of crystalline Z-Gln-OSu is added to the mixture, and the mixture is stirred at -5° C. for 2 hours and allowed to stand at room temperature for 2 days. Then, 2 g of N-(2-aminoethylpiperazine) is added to the reaction mixture, and the mixture is stirred for 30 minutes and added to 2.5 l of 1 N HCl. The formed precipitate is recovered by filtration, washed with water, suspended in 400 ml of methanol, stirred and recovered by filtration to obtain 31.5 g of intended Z-Gln-Arg(Tos)-Leu-Leu-Gln-Gly-Leu-Val-NH2 (the yield being 84.2%).

Provenance & Evidence