Hydrogen Bromide → H-Lys-Gln-Nle-Ala-Val-Lys-NH2

Participants

Reaction Steps

The protected hexapeptide (XV) (0.2 g, 0.2 mmol) was dissolved in TFA (5 ml) and treated with HBr gas over 1 hr. The mixture was evaporated in vacuo and triturated with Et2O (2×50 ml) to give (V) as a hydrobromide salt (0.13 g) RfH=0.14. This and a subsequent batch of product were purified by adsorption on to an ion exchange column (CM 25 Sephadex, Pharmacia) which was washed with 10-100 mmol NH4OAc at pH 7. The product was eluted with 100 mmol NH4OAc at pH 8.5. Lyophilisation and subsequent preparative HPLC [μBondapak ODS.; CH3CN: 50 mmol NH4OAc(aq) (15:85) gave (V) as an acetate salt (0.15 g) mp 253°-255° C. T.l.c. RfH=0.14, MH+ (FAB)=685.

Provenance & Evidence