2ne1

7+ Year Member
Oct 27, 2009
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Sorry, it feels like I am posting questions in every 5 seconds, but I have DAT coming up real soon and got stuck doing practice probs!
Now the question...

benzyl alcohol reacting with HCl and heat will produce what?

I thought it would go through elimination, but since it's a benzene, it cannot.
I checked with Kaplan BB and it said alchols get dehydrated in a strongly acidic solution(like H2SO4) with heat.
The answer says that the -OH group becomes -Cl.....
I thought displacement of hydroxyl groups in substiution rxn is rare since OH- is poor leaving group so if you want to convert the alchol into alkyl halides, you need to use things like SOCl2.
Can anybody clarify this? Thanks!
 
Mar 15, 2010
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In the Mountains
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So you are right! OH is an awful leaving group, but you can make it a better LG by protonating it. H2O is a great leaving group, so it can undergo substitution. The aromaticity of benzene will seldom be interrupted due to its relative stability.

Personally, I would use SOCl2 to get that Cl on there like you, but this reaction should work too.
 

AmpedUp

The Legend Still Lives
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Dec 1, 2009
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Correct. It forms Benzyl Chloride.

Just follow the flow of electrons here...From the oxygen grabbing the hydrogen to form water (good leaving group)...and the chlorine is free which takes the same spot the alcohol once occupied.