The Student Room Group

Making ethanoyl chloride from ethanoic acid

In today's lesson I come across such a reaction:

CH3COOH + SOCl2 -------- CH3COCl + SO2 + HCl

Which converts the ethanoic acid into ethanoyl chloride, with the SOCl2 acting as a nucleophile.

the teacher however does not tell me HOW does this SOCl2 act as a nucleophile, he actually didnt even tell me the bond arrangement of SOCl2 so I am a bit puzzled, and I want to know the detail of this nucleophilic substitution, which part of SOCl2 act as nucleopile an how, and where the SO2 and HCl come from.

Thanks
Reply 1
The o part of socl2 would act as the nucleophill imo. Are you with aqa?
Reply 2
It's easiest to think of SOCl2 contributing a chloride ion, which knocks off the hydroxyl on ethanoic acid. After that, things get a bit complicated.
first, using PCl5 makes it a lot easier.. and Cl- acts as a nucleophile
Chlorination reactions using SOCl2 or PCl5 do not proceed via simple nucleophilic substitution which is why the exam boards do not require the mechanisms.
Reply 5
CH3COOH + A-CL(x) -----> CH3COCL +AOCL(x-2) + HCL.....