[miragelife]

Hello!

I am doing a project for school and I wanted to include this reaction into it: the transformation of 1-chloro-2-(dichloromethyl)benzene into 2-chlorobenzaldehyde.
[attached it, and here is direct link to it: https://www.prepchem.com/synthesis-of-4-chlorobenzaldehyde/ ].

What I want to know is what the mechanism behind this reaction is because i can't figure it out myself. Could anybody help me out with this one?

[miragelife]

I forgot to add the reaction conditions. The reactions takes place in an acidic medium - H2SO4 in the link.

[Babcock_Hall]

Would you please give us your thoughts first?

[miragelife]

I would say something like this might happen. What is bothering me in this mechanism is the acidity. So I added H3O+ in the end to neutralize Cl-. But what if water is mostly arleady protonated at the start. That would probably hinder it's nucleophility right? Do halogen bonds affect do reaction? Can halogen ease the nucleophilic attack of a H3O+?

[Babcock_Hall]

Another possibility is that there is a carbocation intermediate.

[miragelife]

Thank you, I tought of that. The benzene does nicely stabilize the carbocation right

[Babcock_Hall]

Yes, through resonance delocalization.