[Limpet Chicken]

Hey guys.

I was wondering, what would be the best way to selectively replace the second alkyl group on a double ketone such as methyl isobutyl ketone, or methyl ethyl ketone with an aromatic group such as benzene or phenol?

I have been trying to figure out a way, and am not having much sucess, all I could think of is maybe refluxing MEK/MIBK with benzonitrile and reducing, maybe with Hg/Al and just hoping and praying that the it would substitute an aromatic group for the ethyl /isobutyl group, any ideas on whether this will work?

Thanks.

[Donaldson Tan]

acylation?

[Limpet Chicken]

Are we talking friedel-crafts rxn here?

Thanks.

[movies]

Starting from the ketone is probably going to be a dead end.  Friedel-Crafts acylation, as Geodome suggested, is probably your best bet.

You'd need your aromatic and the acid chloride.

Starting from the ketone is going to be very difficult because you have to break a carbon-carbon bond to substitute it.  That's hard to do.

[Limpet Chicken]

I was thinking, starting from the ketone, go from MEK or MIBK to methyl benzyl ketone
(benzene=phenol?), as I have plentiful supplies of MEK/MIBK used for cleaning

[movies]

Oh, so you don't want to do substitution of the ketone, you want to add on an aromatic piece?

[Limpet Chicken]

Yeah, take MEK and turn it into  benzyl ethyl ketone. Sorry, I was a little unclear, I was rather stoned last time I typed that post

[movies]

The first thing that comes to mind is Hartwig's palladium catalyzed alpha arylation chemistry.  That's probably not the most accessible reaction for at-home use however.

Fuchs did some alpha arylation chemistry in the mid 70s using imines as carbonyl surrogates.  That might be more accessible.

[Limpet Chicken]

Movies, could you post a link, or the procedure, to those methods you suggested?
I do have a source, or sorts, for palladium metal catalysts :angel_not:

That second procedure looks interesting however.

[movies]

There are some references on the respective group websites:

http://www.yale.edu/hartwig/Overview.htm
http://www.chem.purdue.edu/fuchs/Publications/Pub197x.html

I can't post the papers themselves, they're copywritten.

I'm not really familiar with the details of the reactions themselves.  The palladium stuff is almost certainly not amenable to a home laboratory.  You would need access to strong bases (t-butoxide), palladium (0), and a rigorously inert atmosphere in addition to the reagents themselves.

The Fuchs stuff is probably a little easier, but I hardly know anything about it.

You might look up so called "S_NAr" chemistry.  I'm not sure if it would be particularly applicable, but it's the same type of reaction that you are looking for.  I think it is essentially the basis for the Fuchs chemistry.  Hope this helps.

[AWK]

Aromatic substitution of double ketones?
I was wondering, what would be the best way to selectively replace the second alkyl group on a double ketone such as methyl isobutyl ketone, or methyl ethyl ketone with an aromatic group such as benzene or phenol?

Let us settle what we are discuss with.
What does mean "double ketone" ?
MEP or DIBK are just ketones, di-ketones possess two carbonyl groups (eq acetoacetone or 2.4 -pentanedione).
The original question was about replacement of an alkyl group - discussion is on substitution.
Benzene or phenol are compounds - not groups.

[Limpet Chicken]

One can have a benzyl or phenyl functional grop can one not?

[AWK]

Benzyl group from which - benzene or phenol?

[Limpet Chicken]

Phenol, to make phenyl/benzyl(forgive me on the nomenclature) acetyl ketone.
Ibelieve the normal way to this (stinks of cat pee ) is to distill the double salt of calcium and phenol/ethanoic acid.