反应详情

B tert-Butyl (2RS,4SR,5SR)-4-(3,3-dimethylpiperidinocarbonyl-1-{2-[3-(3-(ethoxycarbonyl)phenyl]ureido]acetyl}-5-phenylpyrrolidine-2-carboxylate can be prepared as described in Example 17B, but from 2.7 g of tert-butyl (2RS,4SR,5SR)-1-(2-aminoacetyl)-4-(4-(3,3-dimethylpiperidinocarbonyl)-5-phenylpyrrolidine-2-carboxylate and 1.17 g of ethyl 3-isocyanatobenzoate in 120 cm3 of tetrahydrofuran. After treatment, there are obtained 2.3 g of tert-butyl (2RS,4SR,5SR)-4-(3,3-dimethylpiperidinocarbonyl)-1-{2-[3-(3-(ethoxycarbonyl)phenyl]ureido]acetyl}-5-phenylpyrrolidine-2-carboxylate in the form of a foam used as is in the subsequent syntheses.