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Allyl Benzene To 1-Phenyl-2-Bromopropane.
Skip Step 2, As We Want The Markovnikov
Addition Product. Allyl Benzene Costs Maybe $7 Per Gram.
Experimental Procedure
Skip Step 2, As We Want The Markovnikov
Addition Product. Allyl Benzene Costs Maybe $7 Per Gram.
Experimental Procedure
- Reaction Mixture Preparation: In a dry three-necked flask equipped with a reflux condenser and dropping funnel, dissolve allylbenzene (e.g., 10 mmol) in a suitable, non-polar solvent like benzene or hexane (20-30 mL).
- Initiator Addition: Add a catalytic amount of radical initiator, such as benzoyl peroxide (0.1–0.5 mmol), to the solution.
- Hydrobromination: While stirring, add a solution of hydrogen bromide (HBr) in acetic acid or bubble gaseous HBr through the reaction mixture.
- Heating/Initiation: Heat the mixture to reflux (typically 60–80°C) for several hours. The reaction requires heat or light to initiate the homolytic cleavage of the peroxides.
- Workup: Cool the mixture to room temperature. Wash the organic layer with water, followed by a dilute sodium bicarbonate solution
to neutralize any remaining acid. - Purification: Dry the organic layer over anhydrous magnesium sulfate (Epsom salts), filter, and remove the solvent under reduced pressure using a rotary evaporator. The product can be further purified via distillation or column chromatography.
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