Hydrogen Bromide → 5-bromo-2,3-dihydro-1H-indene

Participants

Reaction Conditions

Reaction Steps

5-Aminoindane was treated with concentrated hydrobromic acid. The suspension was cooled to −5° C., and 5M sodium nitrite solution was added at a temperature between 0° C. to 5° C. in period of 30 minutes through an addition funnel. Stirring was continued for 20 minutes at 0° C. to 5° C. The reaction mixture was now very dark fluid slurry. In a second reaction vessel, a solution of copper (I) bromide in concentrated hydrobromic acid had been prepared and preheated to 40° C. When the diazonium salt slurry was added in portions, a very slow gas evolution was observed which became vehement when heating to 60° C. After stirring at 60° C. for 40 min, the gas evolution ceased. The mixture was poured onto water. The product was extracted twice with ethyl acetate. Some of the precipitated copper bromide was removed by filtration to facilitate phase separation. The organic extracts were washed twice with water and one time with brine. The combined organic extracts were dried over anhydrous magnesium sulfate, filtered, and evaporated to dryness. After flash chromatography, the title compound was obtained as pale yellow oil.

Provenance & Evidence