Reaction #10401

Reaction equation

3-chloro-2-cyclopropylamino-4,5-difluorobenzoic acid

tert-butyl carbazate

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

→

title compound

Yield 63.1%

(3-Chloro-2-cyclopropylamino-4,5-difluorobenzoyl)-hydrazinecarboxylic acid tert-butyl ester

Yield 63.1%

Solvents

dichloromethane

dichloromethane

Conditions

Workup

1. 1
   Washwashed with saturated NaHCO3, water, and brine
2. 2
   DryingThe organic layer is dried over MgSO4
3. 3
   Filtrationfiltered
4. 4
   ConcentrationThe filtrate is concentrated under vacuum
5. 5
   Otherpurified via flash column chromatography (1:2 ethyl acetate/hexanes)

Procedure

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+).

Source