Potassium Permanganate → 7-Bromo-4,4-difluoro-3,4-dihydronaphthalen-1(2H)-one

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.

1. customthe organic layer separated
2. washwashed with water (10 ml) and brine (10 ml)
3. dry with materialfinally dried over sodium sulphate
4. customevaporated at reduced pressure
5. customThe crude product was purified by chromatography on silica gel using a gradient of heptane/ethyl acetate=100:0 to 80:20 as the eluent

ORD record

ord-666a61b6300d4c3bafb71a6dad347924

Source dataset

uspto-grants-2015_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09079919B2