Chlorobenzene → (Undec-10-en-1-yl)benzene

Participants

Reaction Conditions

Reaction Steps

Commercial 25 wt. % phenyl magnesium chloride (0.4 mol) in tetrahydrofuran (Acros Organics, AcroSeal bottle) works as described in the following reaction and is transferred to a 250-mL Schlenk flask equipped with a magnetic stirrer, reflux condenser, nitrogen inlet, and rubber septum side arm via cannula under nitrogen. Alternatively, the Grignard is made as follows. A 250 mL, 3-necked flask equipped with a mechanical stirrer, reflux condenser, addition funnel and argon inlet is situated first in a cooled water bath and then later in an oil bath. Under nitrogen, magnesium (0.04 mol) is added to chlorobenzene (0.04 mol) in dry tetrahydrofuran (freshly distilled from sodium benzophenone ketyl, 20 g), and is vigorously stirred for 3 hours. Undecylenyl bromide (0.04 mol) is added, and then CuI (0.02 mol) is added. After refluxing for 24 hours followed by cooling to 23° C., ammonium chloride is added and the solvent is removed. Water is added and the mixture is extracted with methylene chloride. After drying the methylene chloride layer over sodium sulfate and then filtration, the solvent is removed to yield a white crystalline solid and a light-yellow oil. The oil is decanted from the white solid (biphenyl) and then distilled at 150° C. under high vacuum to obtain 11-phenylundecene in 50% yield. By-products which distill over between 23° C. and 150° C. include phenol, undecene, 11-chloroundecene, biphenyl and 11-bromoundecene. Still bottoms remaining after the 11-phenylundecene has distilled over include CH2═CH—(CH2)18—CH═CH2. Without copper(I) iodide, no reaction takes place after 3 days of continuous reflux under the conditions described.

Provenance & Evidence