Triethylamine → rac-(2R,3S,4R,5S)-5-(2-benzyloxycarbonyl-2-methyl-propyl)-3-(3-chloro-2-fluoro-phenyl)-4-(4-chloro-2-fluoro-phenyl)-4-cyano-pyrrolidine-2-carboxylic acid tert-butyl ester

Participants

Reaction Steps

In a manner similar to the method described in Example 100b, 4-[(E)-tert-butoxycarbonylmethylimino]-2,2-dimethyl-butyric acid benzyl ester prepared in Example 103a (4.1 g, 12.3 mmol) was reacted with (Z)-3-(3-chloro-2-fluoro-phenyl)-2-(4-chloro-2-fluoro-phenyl)-acrylonitrile (2.5 g, 8 mmol) prepared in Example 52a, AgF (1.55 g, 12.3 mmol), and triethylamine (2.5 g, 24 mmol) in dichloromethane (150 mL) at room temperature for 18 h, followed by the reaction with DBU (4 ml) in tert-butanol (40 mL) at 100° C. for 4 h to give rac-(2R,3S,4R,5S)-5-(2-benzyloxycarbonyl-2-methyl-propyl)-3-(3-chloro-2-fluoro-phenyl)-4-(4-chloro-2-fluoro-phenyl)-4-cyano-pyrrolidine-2-carboxylic acid tert-butyl ester as a light yellow gum (0.98 g, 19%).

Provenance & Evidence