h0539 - 12-7-2023 at 08:19
Hi. Today I unsuccessfully attempted to synthesise this by bubbling isobutylene through a solution of 10 g catechol dissolved in 200 ml of 50:50
water/ethanol by volume, with 1g of sulfuric acid as a catalyst. I was hoping the insoluble product would precipitate as it formed.
Naturally, it didn't work and the gas just bubbled out of the solution and nothing precipitated. I was wondering if anyone had any pointers as to why
it was unsuccessful.
I was considering using a less polar solvent to dissolve more isobutylene, but the mechanism proceeds via cationic intermediates, so I wasn't sure.
Alternatively, I was considering a Friedel Crafts reaction with an excess of AlCl3, but this seemed more straightforward. Thanks.
DraconicAcid - 12-7-2023 at 14:10
I'm not an expert at FC alkylations, but I'm looking forward to whatever advice you get.
I'd expect that the water in the solution is a much stronger base than the isobutylene, and that's messing up the reaction. You might try a variation
of this procedure: https://www.amherst.edu/system/files/media/0175/Exp14.pdf
If it wasn't for the hydroxyls on your aromatic ring, I'd also suggest FeCl3 and tBuCl in DCM instead of AlCl3 (I know it works on biphenyl), but
phenols and FeCl3 may muck up.