Trifluoroacetic acid → 5-Bromo-4-methylisobenzofuran-1(3H)-one

To a flask charged with (3-bromo-2-methylphenyl)methanol (6.0 g, 30 mmol) was added a 1M TFA solution of Thallium Trifluoroacetate (16.2 g, 29.8 mmol). The mixture was stirred at RT overnight. Analysis by TLC showed no starting material remaining. The solvent was removed under vacuum, and the residue was pumped under high vacuum for 30 min to ensure complete removal of TFA. To the residue was then added Palladium(II) Chloride (529 mg, 2.98 mmol), Lithium Chloride (2.53 g, 59.7 mmol), Magnesium Oxide (2.41 g, 59.7 mmol), and MeOH (150 mL). The reaction was flushed with CO twice, and kept under CO at room temperature. Analysis by LC showed a big product spot within 2 hours. To this solution was added ethyl acetate to precipitate the salts. The black solution was filtered through a celite pad, washed with EtOAc, adsorbed onto silica and purified by silica gel chromatography to afford 5-bromo-4-methyl-2-benzofuran-1(3H)-one.

1. customThe solvent was removed under vacuum
2. waitthe residue was pumped under high vacuum for 30 min
3. customremoval of TFA
4. customThe reaction was flushed with CO twice
5. customkept under CO at room temperature
6. customwithin 2 hours
7. additionTo this solution was added ethyl acetate
8. customto precipitate the salts
9. filtrationThe black solution was filtered through a celite pad
10. washwashed with EtOAc
11. custompurified by silica gel chromatography

ORD-Eintrag

ord-708fa29ce039401eb2cb034778ecfbfa

Quelldatensatz

uspto-grants-2014_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08673920B2