[phth]

Sorry mods if this is in the wrong forum, but I think that my question extends beyond the scope of undergrad o-chem. Please rate the logic of the conclusions I made about the reactions in the pdf.

[Archer]

I need to print this out and read it in more detail. By which time someone else will have no doubt come up with a solution.

I will make one comment though. Interestingly I was doing FC acylations on indane some while ago and folowed my normal protocol of a room temperature reaction and I got two products. One of which was the corresponding, desired, phenone. The other was a mystery as it had similar MS data differing by an extra mass of 14 on the ring.

Keeping the indane cool while it was in contact with the AlCl₃ resolved the issue and I never sought the oportunity to investigate this product, it was a good 30% of the product.

[Archer]

One thing you could try, I have been using this method for FC acylations for many years on countless substrates because it is quick and easy.

The method is lifted from a patent

 US 4053517 A "Method of acylation of phloroglucinol" http://www.google.com/patents/CA1068725A?cl=en

Originally I used it for phloroglucinol but I soon found it to be effective with all FC-acylations that I was using (with only one exception).

This is an extremely reliable method for acylating sensitive substances. Most of the time no heating is necessary. It can even be used at sub-zero temperatures and the reaction is complete within 20 minutes of the acid chloride being added.

This may or may not be any help to you but I thought I would throw it out there. I have found that using this method where toluene is involved dramatically reduces the amount of isomeric 2- & 3- substituted impurities that are observed when toluene is used as the solvent and reactant and heat is applied.

[phth]

Thank you, Archer.  That makes sense.  I will give it a try next time.

[Archer]

The only minor modification to the work up for everything but acylphloroglucinol (which forms insoluble complexes with the aluminium) is that I just pour into ice and remove the organic layer (obviously subsequent washing with DCM ) wash with water, a carbonate solution (if necessary), dry  and remove the solvent.

The only substrate this didn't work with was 1,3-benzodioxole, too labile to AlCl₃ even when cold.

An interesting result was better regioselectivity with naphthalene, in ice the reaction favoured substitution at the 2-position (if memory serves). Whereas at room temperature there was a mixture of almost equal proportions of 1-acylnaphthalene and 2-acylnaphthalene.

With the power of hindsight we subsequently made our acylnaphthalenes via Grignard and nitrille.