Triethylamine → (R)-N5-(Cbz)-N2-(Diphenylacetyl)-(R)-N-[2-hydroxy-1-(4-methoxy-phenyl)ethyl]ornithine amide

Participants

Reaction Steps

Prepared according to the method described in Example 1(d) above from (R)-N5 -(Cbz)-(R)-N-[2-hydroxy-1-(4-methoxyphenyl)ethyl]ornithine amide hydrochloride (3.33 g; 7.37 mmol; from step (b) above), 2-nitrophenyl diphenyl acetate (2.60 g; 8.10 mmol; see Example 1(c) above), triethylamine (2.23 g; 22.11 mmol) and CH2Cl2 (200 mL), reaction time 60 hours. The resulting yellow solution was submitted to aqueous work up, dried, filtered and concentrated to give the crude product as an off-white solid (4.76 g). The crude product was chromatographed twice on silica gel eluting with CH2Cl2 :MeOH (98:2). Concentration of the product containing fractions gave the sub-title compound as a white solid (0.63 g).

Provenance & Evidence