2-Fluoro-6-methoxynaphthalene → 6-Fluoronaphthalen-2-ol

Temperature

0 °C

A flask was charged with 2-fluoro-6-methoxynapthalene (3.80 g, 21.6 mmol) and dichloromethane (86 mL) and cooled to 0° C. in an icebath under a flow of nitrogen. A solution of borontribromide (26 mL of a 1M solution in dichloromethane, 25.9 mmol) was added via cannula. The reaction solution was stirred 15 minutes at 0° C., the cooling bath was removed and the reaction was stirred for 1.5 h at ambient temperature. The reaction was quenched by slowly adding excess 10% aqueous hydrochloric acid. The two-phased reaction mixture was partitioned between ethyl acetate and water. The organic layer was washed (2×, brine), dried (Na2SO4), filtered and concentrated in vacuo to afford a brown gummy solid. Purification by flash chromatography (silica gel; 20% ethyl acetate/hexane) afforded the desired product (3.63 g, 91% yield). Recrystallization from cold ether/hexanes provided the title compound as a colorless powdery solid. mp 118°-120° C.; 1HNMR (300 MHz, DMSO-d6) δ7.11-7.18 (m; 2H), 7.30 (td; J=9,9,3 Hz; 1H), 7.55 (dd; J=10.5,3 Hz; 1H), 7.73-7.79 (m; 2H), 9.73 (s; 1H).

1. customthe cooling bath was removed
2. stirringthe reaction was stirred for 1.5 h at ambient temperature
3. customThe reaction was quenched by slowly adding excess 10% aqueous hydrochloric acid
4. customThe two-phased reaction mixture
5. customwas partitioned between ethyl acetate and water
6. washThe organic layer was washed (2×, brine)
7. dry with materialdried (Na2SO4)
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customto afford a brown gummy solid
11. customPurification by flash chromatography (silica gel; 20% ethyl acetate/hexane)

ORD record

ord-84ad092bd4a34b70a0a6c73c6e47d795

Source dataset

uspto-grants-1998_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05776984