Hydrochloric Acid → Z-6-chloro-3-(5-fluoro-2-methyl-benzylidene)-2-oxo-2,3-dihydro-indole-1-carboxylic acid ethyl ester

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Reaction Conditions

Reaction Steps

To a solution of E/Z-6-chloro-3-(5-fluoro-2-methyl-benzylidene)-1,3-dihydro-indol-2-one prepared in example 145a (0.20 g, 0.71 mmol) in dichloromethane (3 mL) at 0° C. was added ethyl chloroformate (0.10 mL, 1.1 mmol), followed by the addition of triethylamine (0.14 g, 1.4 mmol). The reaction mixture was stirred at 0° C. for 30 minutes. The mixture was then poured into aqueous HCl solution (1 N). The organic layer was separated and the aqueous layer was extracted with ethyl acetate. The organic layers were combined and dried over Na2SO4, and concentrated to give E/Z-6-chloro-3-(5-fluoro-2-methyl-benzylidene)-2-oxo-2,3-dihydro-indole-1-carboxylic acid ethyl ester as a yellow solid. The crude product was purified by chromatography to obtain 75 mg yellow solid (Yield 1.7 g, 30%).

Provenance & Evidence