Reaction #10407

Reaction equation

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

potassium carbonate

triphosgene

tetrahydrofuran

→

title compound

(8-Chloro-1-cyclopropyl-6,7-difluoro-2,4-dioxo-1,4-dihydro-2H-quinazolin-3-yl)carbamic acid tert-butyl ester

Solvents

ethyl acetate

Conditions

Workup

1. 1
   TemperatureThe reaction mixture is refluxed for 90 minutes
2. 2
   WashThe organic layer is washed with water and brine
3. 3
   Dryingdried over MgSO4
4. 4
   Filtrationfiltered
5. 5
   ConcentrationThe filtrate is concentrated under vacuum
6. 6
   Otherpurified via flash column chromatography (1:2 ethyl acetate/hexanes)

Procedure

To a solution of (3-chloro-2-cyclopropylamino-4,5-difluorobenzoyl)-hydrazinecarboxylic acid tert-butyl ester (Example 6c) (1.93 g, 5.34 mmol) in tetrahydrofuran (50 mL) is added potassium carbonate (3.69 g, 26.7 mol) and triphosgene (2.06 g, 6.95 mmol). The reaction mixture is refluxed for 90 minutes, cooled to room temperature, and diluted with ethyl acetate. The organic layer is washed with water and brine, then 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 (1.27 g). MS EI: m/z 386 (M+).

Source