Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Dayne on September 07, 2007, 11:48:54 PM
-
Hi, I am trying to get my head around two practice questions that were assigned for my org chem class.
I am trying to figure out how to synthesize m-iodophenol from benzene. Does anyone have an suggestions? I tried using both electrophillic and nuclephillic aromatic reactions, but I keep getting an ortho or para iodophenol.
Furthermore, I am trying to synthesize CH3-(C=O)-CH2-CH2-C5H6 (4-phenyl-2-butanone ?) from ethyl acetanoate. I can't figure out this one as well.
Some help would be greatly appreciated
-
In the first attachment I've proposed the retrosynthesis of m-iodophenol. Of course - maybe there are better ways to put iodine to benzene's ring (mayby some direct ways ;)).
In the second attachment I've proposed the retrosynthesis of your second target.
-
Thanks a lot. I was pretty close on the first one. But for the second one, I totally forgot about acetoacetic ester synthesis.
-
Neecze, don't forget that the iodine is an ortho-para directing group, so treating iodobenzene with fuming sulphuric acid would yield the ortho and para products.
Here's a possible way for m-iodophenol:
1) Treat benzene with molecular iodine and nitric acid: this will yield iodobenzene.
2) Treat iodobenzene with nitrous acid, together with a reducing agent and a copper salt. This will yield 3-iodo-6-nitrosophenol.
3) Reduce the nitroso group to amino group, and then treat with NaNO2 in the presence of hypophosphorous acid (H3PO2).
-
As the iodine and amino group are both ortho¶ derecting effective,we need add the SO3H group before reducing the nitro to amino.Below attached route might be workable.
[attachment deleted by admin]