tert-butyl N-[(2S)-1-[[(2S)-1-amino-1-oxo-3-phenylpropan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]carbamate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: De-(1,1-dimethylethoxy)carbonylation of Boc-Leu-Phe-NH2 (24.0 g.) was carried out using hydrogen chloride in ethyl acetate (4.4N, 200 ml.) for 2 hr. at room temperature. Upon attempted extraction with ethyl acetate the product unexpectedly entered the saturated aqueous sodium bicarbonate wash solution, which was subjected in its entirety to reverse phase HPLC on octadecylsilated silica gel. The column was washed with water. The product was eluted with methanol and crystallized from ethanol-ether-hexane affording H-Leu-Phe-NH2 as a tan solid (13.0 g., 74% yield, m.r. 127°-131° C.). for 2 hr at room temperature extraction with ethyl acetate the product wash solution, which The column was washed with water The product was eluted with methanol crystallized from ethanol-ether-hexane