benzyl chloride synth

[pink_dust_angel]

in benzyl chloride synth on rhodiums site how concentrated doesthe HCl have to be?

[Rhodium]

Provide a link and tell us exactly which preparation you are referring to - there are several benzyl chloride syntheses on my page.

[pink_dust_angel]

i am talking about

https://www.thevespiary.org/rhodium/Rhodium/chemistry/benzylchloride.html

its the synth that says "Chlorination of benzyl alcohol with conc. HCl "

[Rhodium]

The stronger acid you use, the higher your yields will be. Concentrated 36-37% HCl is the best to use, but you might get away with using the 31% strength too, just compensate by using a larger excess of acid.