[Jazzified]

Hello.  I am currently working on a set of problems, and I am a bit stuck on the following:

Suggest a procedure for preparing pure n-propyl-p-xylene that doesn't require separating it from isopropyl-p-xylene.

I was advised to look into Friedel-Crafts acylation, but that requires an R-C=O group, and I do not need a C=O in my final product.

Any help would be greatly appreciated.  Thanks in advance!

[Yggdrasil]

1)  What are the four formulas that you've come up with?

2)  Look up Friedel-Crafts Acylation.

[Jazzified]

1)  What are the four formulas that you've come up with?

2)  Look up Friedel-Crafts Acylation.

1. n-propyl, isopropyl, and 2 bisubstituted products.

[Yggdrasil]

The question asks for isomeric propyl-toluenes, so the bisusbstituted products (although they might be created during the reaction) would not count as isomers of your first two products.  Think instead about the position of substitution in the ring (i.e. ortho, meta, and para).

As for the relative amounts, think of whether adding an n-propyl or isopropyl group is more likely and what effect sterics would have on the position that your alkyl group gets added.

[Jazzified]

2)  Look up Friedel-Crafts Acylation.

I took your advice, but I noticed that Friedel-Crafts acylation requires an R-C=O group, and I do not need a C=O in my final product.  Would I have to do any reactions after the acylation?  Would you be able to provide any additional help?  Thanks.

[Yggdrasil]

There are various ways to reduce a ketone to an alkyl group.  Two common methods are the Clemmensen reduction and Wolf-Kishner reduction.  They should be easy to find in your o-chem notes or book.

[Jazzified]

There are various ways to reduce a ketone to an alkyl group.  Two common methods are the Clemmensen reduction and Wolf-Kishner reduction.  They should be easy to find in your o-chem notes or book.

Great, thank you!  The Clemmensen reduction wasn't in my book, but Wolff-Kishner was.  Thanks!