反应详情

Scheme 2 shows a method by which the compounds of the present invention can be prepared, by illustrating the synthesis of Example 4, methyl 3-([(2S)-2-[(benzyloxy)carbonyl]amino-3-(1H-4-imidazolyl)propanoyl]-2-[(2-methyl-2-phenylpropyl)amino]-2-oxoethylamino)propanoate. Reaction of β-alanine methyl ester hydrochloride with t-butyl bromoacetate was carried out in methylene chloride in the presence of triethylamine as the base to give 3-(tert-butoxycarbonylmethyl-amino)-propionic acid methyl ester which was then coupled to Cbz-His(trityl) in methylene chloride/acetonitrile with HBTU as coupling agent, and triethylamine as the base. The resulting product was treated with 95% aqueous TFA, to remove the trityl and the t-butyl groups, followed by coupling with β,β-dimethylphenethylamine in methylene chloride/dimethylformamide, with HBTU as coupling agent, and diisopropylethylamine as the base to give the desired product.

1. customcan be prepared