Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: harmonic_op on May 24, 2019, 06:55:42 AM
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Is there a process to protect the para position with the help of sulphonation of phenol and after the overall reaction has completed ,to also remove that so3h from para position without anyloss to the overall yield and product?
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Electrophilic aromatic substitution reactions with phenol don't necessarily even favor the para position. Some reactions strongly favor ortho, actually, such as Kolbe-schmitt: https://www.organic-chemistry.org/namedreactions/kolbe-schmitt-reaction.shtm .
Only bulky groups strongly favor para. OH or O- are both not bulky. Phenol also has problems sometimes with poly-reaction, like with halogenation, depending on solvent.
If this is a real thing, you could also look into ortho-lithiation: https://www.scripps.edu/baran/images/grpmtgpdf/Krawczuk_March_08.pdf
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https://www.masterorganicchemistry.com/2018/11/26/sulfonyl-blocking-groups-aromatic-synthesis/
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^^^Good link above. I probably just should've given that one.
Just to correct myself, I was bored and I read that apparently you can favor para product with sulfonation of phenol. It just depends on temperatures. Higher temps give mostly para as thermodynamic product, lower tempers give ortho as kinetic product. At least according to some random guy on Quora: https://www.quora.com/What-is-a-sulphonation-reaction-of-phenol