7-bromo-4,4-difluoro-2,3-dihydronaphthalen-1-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 6-bromo-1,1-difluoro-1,2,3,4-tetrahydro-naphthalene (691 mg, 2.8 mmol) in tert-butanol (7 ml). A solution of potassium dihydrogenphosphate (769 mg, 5.59 mmol) in water (2 ml) and a solution of sodium phosphate heptahydrate (1.51 g, 5.59 mmol) in water (2 ml) were added. Thereafter, potassium permanganate (670 mg, 4.2 mmol) was added and the reaction mixture stirred at room temperature for 15 hours. For the workup, the mixture was diluted with ethyl acetate (200 ml), the organic layer separated, washed with water (10 ml) and brine (10 ml), finally dried over sodium sulphate and evaporated at reduced pressure. The crude product was purified by chromatography on silica gel using a gradient of heptane/ethyl acetate=100:0 to 80:20 as the eluent. The 7-bromo-4,4-difluoro-3,4-dihydro-2H-naphthalen-1-one (515 mg, 71% yield) was obtained as a colorless oil. the organic layer separated washed with water (10 ml) and brine (10 ml) finally dried over sodium sulphate evaporated at reduced pressure The crude product was purified by chromatography on silica gel using a gradient of heptane/ethyl acetate=100:0 to 80:20 as the eluent