Reaktion #471586

Reaktionsgleichung

5-(2-Methoxy-3-amino-phenyl)-2-methyl-furan-3-carboxylic acid

5-(2-methoxy-3-amino-phenyl)-2-methyl-furan-3-carboxylic acid

boron tribromide

→

5-(2-hydroxy-3-amino-phenyl)-2-methyl-furan-3-carboxylic acid hydrobromide

Ausbeute 46.0%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONUpon completion of the addition
2. 2
   Sonstigethe reaction mixture was reacted at room temperature for 2 hours
3. 3
   Sonstigequenched by addition of 0.5 mL of methanol
4. 4
   Einengenconcentrated under reduced pressure
5. 5
   workup.ADDITIONThe resulting residue was diluted with 10 mL of ethyl acetate
6. 6
   workup.STIRRINGstirred for 30 minutes
7. 7
   FiltrationThe mixture was filtered
8. 8
   Sonstigethe filter cake was dried

Vorschrift

5-(2-Methoxy-3-amino-phenyl)-2-methyl-furan-3-carboxylic acid 53d (370 mg, 1.5 mmol) was dissolved in dichloromethane. The mixture was cooled to 0° C. by an ice-water bath followed by dropwise addition of a solution of boron tribromide in dichloromethane (1 N, 3.6 mL). Upon completion of the addition, the reaction mixture was reacted at room temperature for 2 hours. The reaction was monitored by TLC until the disappearance of the starting materials and quenched by addition of 0.5 mL of methanol. The mixture was stirred for 30 minutes and concentrated under reduced pressure. The resulting residue was diluted with 10 mL of ethyl acetate and stirred for 30 minutes. The mixture was filtered and the filter cake was dried to obtain the title compound 5-(2-hydroxy-3-amino-phenyl)-2-methyl-furan-3-carboxylic acid hydrobromide 53e (240 mg, yield 46%) as a grey solid.

Quelle