[Pico]

The following synthesis of 1-chloro-4-propylbenzene from benzene has a flaw and does not provide exactly this product. Step 1 - HNO3/H2SO4, Step 2 - CH3CH2COCl/AlCl3, Step 3 - Sn/HCl, Step 4 - HNO2, Step 5 - CuCl.

Would step 1 would give a nitro group at position 1, then step two give CH3CH2CO at position three, then step three turns the nitro to NH2?

I'm not sure what would happen in the reaction beyond that. Could somebody please help me out by pointing out what would happen in steps 4 and 5?


Many thanks in advance!

[orgopete]

If step two were to succeed, the substitution would not match that indicated in the product.

Two questions. Do Friedel-Craft acylation reactions work on deactivated benzene rings? How can you get para substitution with nitration and acylation?

[C-hemCards]

Yes, there is something fundamentally wrong with either the name ("propyl") or the reagent ("CH3CH2COCl").

Did you mean propyl chloride instead of the acyl chloride?

[orgopete]

Yes, there is something fundamentally wrong with either the name ("propyl") or the reagent ("CH3CH2COCl").

Did you mean propyl chloride instead of the acyl chloride?

No, check step 3.

[C-hemCards]

Reduction of a ketone by Sn/HCl? I'm not aware of that transformation. Certainly the nitro group would be reduced (SnCl2 being the standard of course).

[kriggy]

Maybe he ment clemensen reduction? Zn,Hg/HCl.  (I would use hydrogen, at least in paper exercise)

@pico: check if your substituents onrient the additional reaction into the right positions

[Hunter2]

The main problem it will not be the para-product. Nitro pushes in meta.

So I would go Benzene.... Propylbenzen....seperate  4-Nitro 1- propylbenzene  from ortho.... Reduction to Amine and Sandmeyer HNO₂CuCl

[orgopete]

Reduction of a ketone by Sn/HCl? I'm not aware of that transformation. Certainly the nitro group would be reduced (SnCl2 being the standard of course).

Oops, you are right. I was crediting the poster with a Clemmensen reduction.

There were several errors in this scheme. I was seeking a contribution from the poster rather than giving a route. I agree with those that have posted the steps and reagents need to be revised to get the indicated product.

Hint: Step 1, Friedel-Crafts acylation with propionyl chloride.
Step 2 is not nitration.

[zsinger]

Hint 2: Think about a group you could put on the ring easily (SO3H) and pull off easily, which might DIRECT your chlorine molecule to the correct Meta-Position.  Read about how the SO3H group is attached and removed (You will find the answer)!
         -Zack

[AlphaScent]

This exercise is all wrong from start to finish.

The Nitration will be meta directing for EAS.

No reduction given for the carbonyl to yield the alkane. 

The Sn/HCl may reduce the Nitro to an aniline which then can be converted to a Cl through Sandmeyer.

Zach is  on the right track.  Sulfonate, add chloride, remove sulfonate through hydrolysis, perform EAS (para directing) then reduce carbonyl. 

[Dan]

Sulfonate, add chloride, remove sulfonate through hydrolysis, perform EAS (para directing) then reduce carbonyl.

What is the purpose of sulfonation? You can make chlorobenzene from benzene in one step.

[AlphaScent]

I am silly, didnt think this through enough.  There is no purpose.  I was just thinking about sulfonate being meta directing.

Why give such a convoluted scheme to say what is wrong when most of it is wrong.

Why not just make chlorobenzene: Cl2 and FeCl2, FC acylation, then reduce carbonyl.