Boron tribromide → (R)-3-bromo-2-hydroxy-N-(4-hydroxyphenyl)-2-methylpropanamide

Temperature

0 °C

(R)-3-bromo-2-hydroxy-N-(4-methoxyphenyl)-2-methylpropanamide (6b) (0.55 g, 1.91 mmol) was dissolved in 25 mL of anhydrous methylene chloride in a dry 250 mL round-bottomed flask fitted with a stirring bar, anitrogen inlet and rubber stopper. BBr3 solution (16.0 mL of 0.5 M CH2Cl2 solution, 8.0 mmol) was added dropwise with stirring at 0° C. The reaction solution was stirred at room temperature overnight. The reaction was quenched by adding 20 mL of water and extracted with EtOAc (3×30 mL). The EtOAc layers were separated and dried over anhydrous MgSO4. The solvent was removed under reduced pressure. The residue was purified by flash column chromatography (silica gel, EtOAc/hexanes=1/1 v/v) to give a white solid product, (R)-3-bromo-2-hydroxy-N-(4-hydroxyphenyl)-2-methylpropanamide (6e), 0.51 g, 97.9% yield.

1. customfitted with a stirring bar, anitrogen inlet
2. stirringThe reaction solution was stirred at room temperature overnight
3. customThe reaction was quenched
4. additionby adding 20 mL of water
5. extractionextracted with EtOAc (3×30 mL)
6. customThe EtOAc layers were separated
7. dry with materialdried over anhydrous MgSO4
8. customThe solvent was removed under reduced pressure
9. customThe residue was purified by flash column chromatography (silica gel, EtOAc/hexanes=1/1 v/v)

ORD record

ord-7b4752d2cae64fe381d5c813d95e7172

Source dataset

uspto-grants-2014_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08637706B2