Reaktion #7901

Reaktionsgleichung

3-amino-5-bromopyridin-2-ol

3-Amino-5-bromopyridin-2-ol

triethylamine

4-trifluoromethylbenzoyl chloride

Potassium carbonate

→

title compound

Ausbeute 60.0%

N-(5-Bromo-2-hydroxypyridin-3-yl)-4-trifluoromethylbenzamide

Ausbeute 60.0%

Lösungsmittel

tetrahydrofuran

ethyl acetate

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwarmed to room temperature for 15 h
2. 2
   workup.STIRRINGthe reaction mixture was stirred at room temperature for 6 h
3. 3
   Waschenwashed with saturated ammonium chloride solution and brine
4. 4
   TrocknenThe separated organic layer was dried with sodium sulfate
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated in vacuo
7. 7
   SonstigePurification by medium pressure liquid chromatography on silica gel (1:5 ethyl acetate/hexanes)

Vorschrift

To a solution of 3-amino-5-bromopyridin-2-ol from Step C (1.5 g, 7.9 mol) and triethylamine (1.64 mL, 11.9 mol) in tetrahydrofuran (15.8 mL) at 0 C was added dropwise 4-trifluoromethylbenzoyl chloride (1.2 mL, 7.9 mol). The reaction mixture was stirred at 0° C. for 1 h and warmed to room temperature for 15 h. Potassium carbonate (1.64 g, 11.9 mol) and methanol (15.8 mL) were added and the reaction mixture was stirred at room temperature for 6 h. The reaction mixture was diluted with ethyl acetate (100 mL) and washed with saturated ammonium chloride solution and brine. The separated organic layer was dried with sodium sulfate, filtered and concentrated in vacuo. Purification by medium pressure liquid chromatography on silica gel (1:5 ethyl acetate/hexanes) gave 1.72 g (60%) of the title compound.

Quelle