1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → (3-Chloro-2-cyclopropylamino-4,5-difluorobenzoyl)-hydrazinecarboxylic acid tert-butyl ester

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Reaction Steps

To a solution of 3-chloro-2-cyclopropylamino-4,5-difluorobenzoic acid (Example 5d, 2.09 g, 8.45 mmol) in dichloromethane (30 mL) is added tert-butyl carbazate (1.67 g, 12.7 mmol) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (2.43 g, 12.7 mmol). After 16 hours, the reaction mixture is diluted with dichloromethane and washed with saturated NaHCO3, water, and brine. The organic layer is dried over MgSO4 and filtered. The filtrate is concentrated under vacuum and purified via flash column chromatography (1:2 ethyl acetate/hexanes) to afford the title compound (1.93 g). MS EI: m/z 360 (M+).

Provenance & Evidence