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Our class 12 text book says that if we treat phenol with mixture of concentrated $\ce {HNO3}$ and $\ce{H_2SO_4}$, instead of nitration, the ring is oxidized to quinone.

So, the book proposes that we should treat phenol with $\ce{NaNO2}$ and $\ce{HCl}$ to yield 4-nitrosophenol, and oxidize it to nitrophenol.

However, I could not find this method in any other standard organic chemistry textbook (eg. the book by Clayden, or by Solomons and Fryhle).

Is there any book/source where this particular reaction is illustrated in details?

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  • $\begingroup$ The nitrosation of phenol with NaNO2 and sulfuric acid is described here: thepharmacistpharma.blogspot.com/2009/04/… and the nitrosation of the related 2-Me-phenol is described here prepchem.com/synthesis-of-2-methyl-4-nitrosophenol $\endgroup$
    – Waylander
    Oct 15, 2018 at 15:08
  • $\begingroup$ Thanks. But I am looking for some textbooks $\endgroup$ Oct 15, 2018 at 15:23
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    $\begingroup$ 1. When you use conc. HNO3 and H2SO4 for your nitration, it will lead to formation of picric acid, not quinone or any nitrophenol. Are you sure your textbook reaction is true? 2. Dilute nitric acid serves the nitration to 4-nitrophenol without needing to go through 4-nitrosophenol (although this reaction will also give 2-nitrophenol). Can you confirm why do you need the reaction to go through nitrosophenol? Do you want your end product to be pure 4-nitrophenol? $\endgroup$ Aug 21, 2022 at 6:04

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I don't know about any books but from what I know the best way to do the conversion is to make an ester(PhOCOCH3). This deactivates the ring enough so that it will not get oxidised by nitric acid.

Then treat it with conc. H2So4. This will block the para position. Otherwise, we will get almost no ortho-nitro product due to hindrance due to the ester.

The we use HNO3/H2SO4 to add a nitro group to the ortho position (only available position).

Hydrolyze the above product to get ortho-nitrophenol.

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    $\begingroup$ The question was about paranitrophenol, not ortho. $\endgroup$ Aug 21, 2022 at 0:58

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