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 trifluoroacetic acid solution of thallium trifluoroacetate (16.2 g, 29.8 mmol). The mixture was stirred at room temperature overnight. The solvent was removed under vacuum, and the residue was pumped under high vacuum for 30 minutes 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 methanol (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® diatomaceous earth 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 minutes
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® diatomaceous earth pad
10. washwashed with EtOAc
11. custompurified by silica gel chromatography

ORD-Eintrag

ord-6ad1df555dff48b984da1361189e59aa

Quelldatensatz

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09108947B2