Boron tribromide → 5-(3-Amino-2-hydroxy-phenyl)-furan-2-carboxylic acid hydrobromide

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Reaction Steps

5-(3-Amino-2-methoxy-phenyl)-furan-2-carboxylic acid 9b (2.79 g, 11.97 mmol) was dissolved in 25 mL of dichloromethane followed by dropwise addition of boron tribromide (23.9 mL, 2.0 mol/L). The reaction mixture was reacted at room temperature for 1 hour. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was concentrated under reduced pressure after 5 mL of methanol was added. The residue was diluted with 100 mL of ethyl acetate and stirred for 1 hour. Then the mixture was filtered and the filter cake was dried to obtain the title compound 5-(3-amino-2-hydroxy-phenyl)-furan-2-carboxylic acid hydrobromide 9c (1.24 g, yield 47.2%) as a yellow solid.

Provenance & Evidence