Triethylamine → Ammonia

Participants

Reaction Steps

To a mixture of 1.0 g (3.13 Mol) of Boc-D-Arg(NO2)-OH, 0.57 g (3.28 mMol) of tyramine-hydrochloride, 0.91 ml (0.66 g =6.53 mMol) of triethylamine and 20 ml of anhydrous acetonitrile were added 1.05 g (3.27 mMol) of TBTU, with stirring and external cooling with ice water. The mixture was allowed to come up to ambient temperature and stirring was continued overnight under these conditions. The precipitate was filtered off, the filtrate was evaporated down in vacuo, the residue was distributed between water and ethyl acetate. The ethyl acetate phase was then purified by column chromatography on silica gel (Macherey-Nagel, 35-70 mesh ASTM) using dichloromethane/methanol/cyclohexane/conc. aqueous ammonia =68/15/15/2 (v/v/v/v). 0.8 g (58% of theory) of the title compound were obtained in the form of an amorphous foam, Rf 0.49 (Macherey-Nagel Polygram® SIL G/UV254, ready-made films for TLC; eluant: dichloromethane/methanol/cyclohexane/conc. aqueous ammonia =68/15/15/2 (v/v/v/v)).

Provenance & Evidence