4,4'-Dichlorodiphenylmethane → 1,1'-(4-Chlorobutane-1,1-diyl)bis(4-chlorobenzene)

A solution of 4,4′-dichlorodiphenylmethane (4.37 g, 18.4 mmol) (Blackwell, J. et all, J. Chem. Soc., 1961, 1405) in dry tetrahydrofuran (50 ml) was treated at 0° C. with butyllithium (12.1 ml of 1.6 M, 19.36 mmol) added dropwise over 15 min. After 15 min, the red solution was then added dropwise to a cold (−78° C.) solution of 1-chloro-3-iodopropane (15.0 g, 73.4 mmol) in dry tetrahydrofuran (120 ml). After 20 min at −78° C., the reaction mixture was quenched by the addition of saturated ammonium chloride (100 ml) and diluted with toluene. The organic phase was washed with brine and dried. The oil obtained after evaporation of the solvent was purified on silica gel (elution hexane-toluene 85:15) and distilled under vacuum to give 2.54 g (44%) of the title material as a clear oil: bp 110-130° C./1.5 torr (air bath temperature).