Reaction #10400

Reaction equation

2-(2,4-difluoroanilino)-4,5-difluorobenzoic acid

tert-butyl carbazate

1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide

→

[2-(2,4-difluoroanilino)-4,5-difluorobenzoyl]-hydrazinecarboxylic acid tert-butyl ester

Yield 72.5%

Solvents

dichloromethane

dichloromethane

Conditions

Workup

1. 1
   Washwashed with saturated NaHCO3, water, and brine
2. 2
   DryingThe organic layer is dried over Na2SO4
3. 3
   Concentrationconcentrated under vacuum
4. 4
   Otherpurified via column chromatography (1:3 ethyl acetate/hexanes)

Procedure

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+).

Source