Hydrogen Bromide → 6-Bromo-1-tetralone

Participants

Reaction Conditions

Reaction Steps

To a suspension of 6-amino-3,4-dihydro-2H-naphthalen-1-one (20.5 g, 127 mmol) in 25% HBr (aq) (1017 ml) at 0° C. was added a solution of sodium nitrite (10.53 g, 153 mmol) in water (50 ml) dropwise at a rate as to maintain the temperature below 3°. The cooled reaction mixture was then added to a cooled solution of copper(I) bromide (18.79 g, 131 mmol) in HBr (98 ml, 865 mmol). When the addition was done, the reaction mixture was stirred at 0° C. for 1 h, then warmed to rt. Water (380 mL) was added and the product was extracted with a mixture of Et2O/EtOAc (8:2, 3×). The organic layer was dried over Na2SO4, filtered, and concentrated in vacuo to give a dark brown crude oil. The crude was purified by distillation (3 mm Hg) to give 16.415 g of 6-bromo-3,4-dihydro-2H-naphthalen-1-one.

Provenance & Evidence