Preparation of Benzyl Chloride from Toluene

A sodium hypochlorite solution, containing one molecular proportion of active chlorine is well stirred with 3 molecular proportions of toluene and the mixture cooled to -5° C. or below. One half a molecular proportion of dilute sulphuric acid is then gradually added during six hours, instead of sulphuric acid, hydrochloric acid, boric acid, carbonic acid, acetic acid, etc., or an acid salt, such as sodium hydrogen sulphate, may be used. After standing the two layers are separated and the product of reaction distilled. Unchanged toluene passes over first, followed by pure benzylchloride. The residue contains a small quantity of benzal chloride, and 2% to 3% of highly chlorinated products. The yield of benzylchloride is about 60% to 70% of the theoretical yield calculated on the active chlorine present. 

If larger amounts of hypochlorite are used the product contains correspondingly higher percentages of benzalchloride. For the purposes of preparing benzalchloride however, it is better to start with pure benzylchloride instead of toluene. 

One molecular proportion of benzylchloride is emulsified with a hypochlorite solution containing one-half of a molecular proportion of active chlorine and cooled to -5° C., or below. The equivalent quantity of dilute acid is then added within six to eight hours. After disappearance of the hypochlorous acid the product is separated from the aqueous solution. The benzalchloride is separated from unaltered benzylchloride and obtained pure by fractional distillation. Source Levinstein 1919 

---