1,2-Dichloroethane → Larazotide

Participants

Reaction Conditions

Reaction Steps

Boc-Gly-Gly-Val-Leu-OH (1.0 eq.) (SEQ ID NO 17), H-Val-Gln-Pro-Gly-OtBu (SEQ ID NO 18) (1.0 eq.) and Hobt (1.1 eq.) were dissolved in DMA at room temperature until a clear solution was obtained. The solution was cooled to about −5° C. and EDC (1.1 eq.) was added to the solution to initiate the coupling. The mixture was stirred at −5° C. until completion of the coupling (progress of reaction was followed by HPLC). The reaction mixture was diluted by addition of water what made the peptide precipitate. The solid was filtered, washed with an aqueous solution of KHSO4, with an aqueous solution of NaHCO3 and finally with water. The solid was dried under reduced pressure. To remove the Boc group, the protected octapeptide was dissolved in AcOH and HCl 4M in dioxane (12 eq.) was added. The mixture was stirred at 25° C. for about 2 h. The final peptide was recovered by precipitation in IPE at 25° C. The solid was filtered, washed several times with IPE and finally with MeCN. After drying under vacuum at 40° C., 80% of HCl.H-Gly-Gly-Val-Leu-Val-Gln-Pro-Gly-OH (SEQ ID NO 1) was recovered. The peptide was solubilised in a 0.05M ammonium acetate buffer solution at 25° C., adjusted to 4.5≦pH<5.0 with a 25% NH3 solution, and then diluted with MeCN. This solution was filtered and purified as described in example 9.

Provenance & Evidence