Hydrochloric Acid → HCID 178525815, compound

Participants

Reaction Steps

35 ml of water and 5.0 ml of 1N sodium hydroxide solution are added to 1.92 g of Z-Pro-Phe-His-OMe (H. Derwald et al., J. Med. Chem. 7, 50 [1964]) dissolved in 50 ml of methanol. The solution is stirred for 45 minutes at 25° and then neutralised with 5.0 ml of 1N hydrochloric acid. The solvent is removed and the residue is flash-chromatographed over 10 g of silica gel (eluant: chloroform/methanol/concentrated aqueous ammonia solution [5:3:1]; fractions of approximately 15 ml). Fractions 6-13 are combined, concentrated by evaporation and the residue is dissolved in 70 ml of water. After neutralisation to a pH value of 5.0 by the addition of dilute hydrochloric acid, extraction is carried out twice with n-butanol and the combined butanol phases are washed with water and concentrated by evaporation. After drying the residue in a high vacuum, Z-Pro-Phe-His-OH is obtained in the form of a colourless powder; Rf (I)=0.23.

Provenance & Evidence