Sodium Sulfite → 5-amino-4-bromo-2,2,6,7-tetramethyl-1-benzofuran-3(2H)-one

Temperatur

0 °C

Tetrabutylammonium tribromide (31.0 g, 64.2 mmol) was added to a tetrahydrofuran solution (200 mL) containing 5-amino-2,2,6,7-tetramethyl-1-benzofuran-3(2H)-one (6.59 g, 32.1 mmol) synthesized in Reference Example 20 at 0° C., and the mixture was stirred at 0° C. for 2 hours. To the mixture, a saturated sodium sulfite aqueous solution was added, and extraction was performed using ethyl acetate. The extract was dried using anhydrous magnesium sulfate. After that, the solvent was removed under reduced pressure, and the obtained residue was purified by silica gel column chromatography (hexane-ethyl acetate 98:2 to 85:15) to give 6.60 g of the title compound (yield: 72%).

1. customsynthesized in Reference Example 20 at 0° C.
2. extractionextraction
3. customThe extract was dried
4. customAfter that, the solvent was removed under reduced pressure
5. customthe obtained residue was purified by silica gel column chromatography (hexane-ethyl acetate 98:2 to 85:15)

ORD-Eintrag

ord-b18b6ddd688442f09fe6a12eec2f3e05

Quelldatensatz

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08957069B2