Hydrochloric Acid → 7-bromo-5-hydroxy-3,4-dihydro-2H-naphthalen-1-one

Temperature

100 °C

To a mixture of tris(dibenzylideneacetone)dipalladium(0) (210 mg, 0.23 mmol), di-tert-butyl-(2′,4′,6′-triisopropyl-biphenyl-2-yl)-phosphane (403 mg, 0.92 mmol), and potassium hydroxide (1.67 g, 25.32 mmol) were added degassed water (5.25 mL) and a solution of 5,7-dibromo-3,4-dihydro-2H-naphthalen-1-one (3.5 g, 11.51 mmol) in dioxane (7.0 mL) at room temperature under nitrogen. The resulting suspension was heated to 100° C. for 3.5 h. The reaction mixture was then cooled to room temperature, diluted with water (˜10 mL) and acidified with 1N HCl solution. The resulting mixture was extracted with ethyl acetate (2×100 mL) and the combined organic extracts were washed with brine (200 mL), then dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The crude product was purified by chromatography, using an ISCO (120 g) column (gradient elution with 5-30% ethyl acetate in hexanes) to obtain 7-bromo-5-hydroxy-3,4-dihydro-2H-naphthalen-1-one (0.45 g, 16%) as a white solid: ES(−)-HRMS m/e calcd. (calculated) for C10H9O2Br (M−H)− 238.9713, obsd. (observed) 238.9712. Two other side products were also isolated and characterized as 5-bromo-7-hydroxy-3,4-dihydro-2H-naphthalen-1-one (0.3 g, 10%) and 5,7-dihydroxy-3,4-dihydro-2H-naphthalen-1-one (0.191 g, 7%).

1. additionwere added
2. customdegassed water (5.25 mL)
3. customat room temperature
4. temperatureThe reaction mixture was then cooled to room temperature
5. extractionThe resulting mixture was extracted with ethyl acetate (2×100 mL)
6. washthe combined organic extracts were washed with brine (200 mL)
7. dry with materialdried over anhydrous magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe crude product was purified by chromatography
11. washan ISCO (120 g) column (gradient elution with 5-30% ethyl acetate in hexanes)

ORD record

ord-9a6e199320ca4122af4ae912527f55a4

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08263656B2