Reaktion #52990

Reaktionsgleichung

4-Amino-2,6-dichlorobenzoic acid methyl ester

NaNO2

HBr

→

4-bromo-2,6-dichlorobenzoic acid methyl ester

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was warmed up to 100° C
2. 2
   workup.STIRRINGThe mixture was then stirred at 100° C. for 30 min
3. 3
   Extraktionextracted with AcOEt
4. 4
   TrocknenThe extract was dried (MgSO4)
5. 5
   Filtrationfiltered
6. 6
   Sonstigeevaporated
7. 7
   SonstigeThe residue was purified by column chromatography (silica gel; eluent: hexane and AcOEt 50:1)

Vorschrift

4-Amino-2,6-dichlorobenzoic acid methyl ester (1.00 g) was suspended in 40% aq. HBr and the mixture was cooled lto 0-5° C. After NaNO2 (376 mg) was added in small portions, the mixture was stirred for about 5 min. Copper (100 mg) was added and the mixture was warmed up to 100° C. The mixture was then stirred at 100° C. for 30 min, diluted with water and extracted with AcOEt. The extract was dried (MgSO4), filtered and evaporated. The residue was purified by column chromatography (silica gel; eluent: hexane and AcOEt 50:1) to give 4-bromo-2,6-dichlorobenzoic acid methyl ester (1.07 g).

Quelle