Hydrochloric Acid → HCID 70048334, compound

Participants

Reaction Steps

Hydrogen chloride gas was passed through a stirred, ice cold solution of N-{1-[3-(N2,N6 -dibenzyloxycarbonyl-(S)-lysylamino)-2-t- butryloxycarbonylpropyl]-1-cyclopentanecarbonyl}-O-t-butyl-(S)- tyrosine-t-butyl ester (from Example 81, 0.445 g, 0.47 mmole), and anisole (0.765 g, 7.1 mmole) in dry dichloromethane (10 ml) until saturation was achieved. A precipitate formed. After stirring for 1.5 hours, the solvent was evaporated under reduced pressure, and the residue azeotroped with dry dichloromethane. The residue was partitioned between ethyl acetate and aqueous sodium bicarbonate. The phases were separated, and the organic phase washed with two further portions of aqueous sodium bicarbonate. The combined aqueous phases were re-extracted with diethyl ether, and then acidified with 1M hydrochloric acid to pH 2. The aqueous phase was extracted with ethyl acetate (2x) and the combined organic phases dried (MgSO4), filtered and the solvent evaporated to yield a foam, which was azeotroped with methylene chloride to yield the title compound as a solid foam (0.325 g, 89%). Found: C,62.81; H,6.68; N,6.92. C41H50N4O11 0.4 CH2Cl2 requires C.61.17; H,6.33; N,6.93%.

Provenance & Evidence