Hydrochloric Acid → 7-Bromo-1-fluoronaphthalene

Participants

Reaction Steps

A solution of the product from Step A (5 g, 21 mmol) in methyl tert-butyl ether (20 ml) was treated with a solution of hydrogen chloride in diethyl ether (16.9 ml, 2 M) and the resulting mixture was stirred at room temperature. After 30 minutes, solids had precipitated and were filtered and washed with methyl tert-butyl ether. These solids were added to 6 M HCl (57.7 ml) and the resulting suspension was cooled to 0° C. Sodium nitrite (4.7 g, 70 mmol) followed by sodium tetrafluoroborate (7.4 g, 70 mmol) were added portionwise keeping the temperature at 0° C. The mixture was stirred at 0° C. for 30 minutes, then filtered. The filtrate was washed with ice cold water and extracted with ice cold methyl tert-butyl ether to give 7-bromo-1-fluoronaphthalene (4 g, 85%): 1H NMR (300 MHz, DMSO-d6) δ 8.18 (d, J=1.8 Hz, 1H), 7.97 (dd, J=9.0, 1.8 Hz, 1H), 7.80 (d, J=8. Hz, 1H), 259-7.72 (dd, J=8.7, 2.1 Hz, 1H), 7.55 (td, J=7.8, 5.4 Hz, 1H), 7.39 (ddd, J=10.8, 7.8, 0.9 Hz, 1H).

Provenance & Evidence