Toluene → 1-(2-Bromoethyl)-4-chlorobenzene

Participants

Reaction Steps

A 500 ml. 3 neck round bottomed flask under nitrogen was charged 15.65 g. of 4-chlorophenethanol (1.0 eq., 0.10 moles) in 60 ml. toluene. To the reaction was added dropwise 41.6 g of thionyl bromide (2.0 eq., 0.20 moles) in 15 ml. of toluene maintaining the temp. below 25 C. Finally, 8.7 g. pyridine (1.1 eq., 0.11 moles) in 20 ml. toluene was added dropwise again keeping the temperature below 30° C. with an external ice bath. The reaction was monitored by GLC and after 1 hr. an additional 14.0 g of thionyl bromide (0.67 eq. 0.067 moles) was added followed three hours later by 9.7 gms. (1.1 eq., 0.11 moles). Subsequently 4.3 g. of pyridine was added (0.55 eq., 0.055 moles) after which GLC indicated all the alcohol was consumed. The reaction was quenched by the addition of 300 ml of water while cooling with an ice bath after which 400 ml. of ether was added. The ether was washed water three times with 250 ml.), dried over MgSO4 and concentrated to give 14.4 g of product as an oil (65.2% yield).

Provenance & Evidence