Boron tribromide → 2-Bromo-5-hydroxybenzaldehyde

To the solution of 2-bromo-5-methoxy-benzaldehyde (10 g, 46.5 mmol) at −78° C. is added BBr3 (25 g, 93.75 mmol) and allowed to warm to room temperature. After 2 h, the reaction is quenched with water and extracted with ethyl acetate. The combined organic layers are washed with water, brine, dried over MgSO4, concentrated and purified by column chromatography to afford 3.6 g of 2-bromo-5-hydroxy-benzaldehyde. To the solution of 2-bromo-5-hydroxy-benzaldehyde (1.45 g, 7.2 mmol in benzene (30 ml) and THF (6 ml) is added 1,3-propanediol (2.74 g, 36 mmol) and TsOH (37 mg, 0.22 mmol). The mixture is refluxed for 24. After cooling down, the solvent is evaporated. The residue is loaded on silica and purified by column chromatography to afford the titled compound (2.3 g) as brown oil.

1. customthe reaction is quenched with water
2. extractionextracted with ethyl acetate
3. washThe combined organic layers are washed with water, brine
4. dry with materialdried over MgSO4
5. concentrationconcentrated
6. custompurified by column chromatography

ORD record

ord-a8926b7aa74b44d3a50d3d9075ef4266

Source dataset

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07816557B2