Triethylamine → rac-(2'R,3'S,4'S,5'R)-6-chloro-4'-(3-chloro-2-fluoro-phenyl)-2'-(2,2-dimethyl-propyl)-2-oxo-1,2-dihydro-spiro[indole-3,3'-pyrrolidine]-5'-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of [3,3-dimethyl-but-(E)-ylideneamino]-acetic acid tert-butyl ester (2 g, 9.4 mmol) prepared in Example 1 and E/Z-6-chloro-3-(3-chloro-2-fluoro-benzylidene)-1,3-dihydro-indol-2-one (2.3 g, 7.5 mmol) prepared in Example 2 in dichloromethane (30 mL) were added triethyl amine (2.8 mL, 20 mmol) and AgF (1.1 g, 8.7 mmol). The mixture was stirred at room temperature for 3 h. The mixture was concentrated, and the residue was partitioned between ethyl acetate and brine. The organic layer was separated, washed with water, dried over MgSO4, and concentrated. The residue was purified by chromatography (EtOAc:hexanes=1:3, 1:2) to give as rac-(2′R,3′S,4′S,5′R)-6-chloro-4′-(3-chloro-2-fluoro-phenyl)-2′-(2,2-dimethyl-propyl)-2-oxo-1,2-dihydro-spiro[indole-3,3′-pyrrolidine]-5′-carboxylic acid tert-butyl ester a white foam (1.9 g, 49%)

Provenance & Evidence