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

Participants

Reaction Steps

In a manner similar to the method described in Example 1c, [3-methyl-but-(E)-ylideneamino]-acetic acid tert-butyl ester prepared in Example 1a (5 mmol) was reacted with give (Z)-2-(4-chloro-2,5-difluoro-phenyl)-3-(3-chloro-2-fluoro-phenyl)-acrylonitrile (1.3 g, 3 mmol) prepared in Example 109a, AgF (0.77 g, 6 mmol), and triethylamine (1.4 mL, 10 mmol) in dichloromethane (120 mL) at room temperature for 18 h, followed by the reaction with DBU (4.8 ml) in tert-butanol (20 mL) at 100° C. for 2 h to give rac-(2R,3R,4R,5S)-4-(4-chloro-2,5-difluoro-phenyl)-3-(3-chloro-phenyl)-4-cyano-5-(2,2-dimethyl-propyl)-pyrrolidine-2-carboxylic acid tert-butyl ester as a light yellow gum (1.5 g, 69%).

Provenance & Evidence