Guaiacol → 5-Bromo-2-methoxyphenol

To a solution of guaiacol (5.0 g, 0.04 mol) in acetonitrile (50 ml) at ambient temperature, was added trifluoroacetic anhydride (6.2 ml, 1.1 eq.). The solution was stirred for 5 min., then 1 M potassium tert-butoxide (4.0 ml, 0.1 eq.) was added slowly. The resultant mixture was stirred for 45 min. A solution of N-bromosuccinimide (7.83 g, 1.1 eq.) in acetonitrile (50 ml) was added via addition funnel slowly. The orange solution was stirred for 24 hours then the solvent was removed in rotary evaporator to give a residue which was suspended in dichloromethane (50 ml). A 6 N aqueous solution of sodium hydroxide (20 ml) was added and the organic layer was separated and discarded. The aqueous basic layer was acidified with concentrated hydrochloric acid until pH 2 was reached. Dichloromethane (50 ml) was added to extract the acidic aqueous layer. After being separated, the organic layer was washed with brine and concentrated on rotary evaporator to afford the desired product (8 g) as a redish oil in 90% yield.

1. stirringThe orange solution was stirred for 24 hours
2. customthe solvent was removed in rotary evaporator
3. customto give a residue which
4. customthe organic layer was separated
5. additionDichloromethane (50 ml) was added
6. extractionto extract the acidic aqueous layer
7. customAfter being separated
8. washthe organic layer was washed with brine
9. concentrationconcentrated on rotary evaporator

ORD record

ord-17907cf5d9174d4e9719df89cd38177b

Source dataset

uspto-grants-2003_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06624323B1