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

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Reaction Steps

To a solution of 2-(2,4-difluoroanilino)-4,5-difluorobenzoic acid (Example 5, 2.18 g, 7.6 mmol) and tert-butyl carbazate (1.57 g, 11.8 mmol) in dichloromethane (30 mL) is added 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (2.25 g, 11.77 mmol). After stirring for 16 hours at room temperature, the reaction mixture is diluted with dichloromethane and then washed with saturated NaHCO3, water, and brine. The organic layer is dried over Na2SO4, concentrated under vacuum, and purified via column chromatography (1:3 ethyl acetate/hexanes) to afford [2-(2,4-difluoroanilino)-4,5-difluorobenzoyl]-hydrazinecarboxylic acid tert-butyl ester as a solid (2.20 g). MS EI: m/z 400 (M+).

Provenance & Evidence