Questions tagged [phenols]

Use this tag for questions about phenols, their synthesis, analysis, properties and more. Do not use the 'alcohols' tag for phenols due to the differences between the two classes.

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Mechanism of Hypervalent Iodine Phenolic Coupling

I need some help understanding the hypervalent iodine phenolic coupling reaction taking place in this synthesis of morphine, the reaction uses $\ce{PhI(OAc)2}$ as the hypervalent reagent and ...
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616 views

Why does phenol react on oxygen in the Gattermann–Koch reaction?

When discussing the Gattermann–Koch reaction on phenol substrates, it has been said that O-acylation is a problematic competing reaction as in a phenol, there's high electron density on the O atom [...
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2k views

Why is o-fluorophenol a stronger acid than p-fluorophenol?

The $\mathrm{p}K_\mathrm{a}$ value of o-fluorophenol is $8.7$, while that of the p-fluorophenol is $9.9$. It's obvious that the inductive effect is more dominant at ortho-position, which results in a ...
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50 views

How much oxygen is used up by the browning of an apple?

This is inspired by a recent popular question on Cooking. Let's assume that I take some apples, cut them up, and place them in a hermetically sealed container. Then the container goes into the fridge. ...
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559 views

Diazo Coupling reaction with para-substituted phenol?

Usually Diazo coupling occurs at para-position unless the para-position is occupied, in which case coupling occurs at ortho-position. While solving questions I found in both the cases as shown, the ...
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796 views

Mechanism of oxidation of phenol to quinone by chromium(VI)

In the supplementary information for Org. Lett. 2005, 7 (19), 4297–4300, the following experimental method for the synthesis of 2-bromo-6-methylcyclohexa-2,5-diene-1,4-dione is given: To a ...
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16 views

Which one out of a keto group or a hydroxyl group would get protonated first if both are present in a compound (attachment)

In the solution provided by my teacher he protonated the ketone, moved the +ve above by resonance did methyl shift and then did dehydration to form a benzene type system. Is this only because for this ...
2
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95 views

Acidic strength of phenol derivatives

While comparing the strengths of o-nitrophenol and p-nitrophenol, p-nitrophenol is found to be more acidic. The reason I studied for this is $\ce{H}$-bonding in o-nitrophenol which makes the acid more ...
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178 views

Addition of NaBH4 and LiAlH4

NaBH4 and LiAlH4 will be a source for the hydride ion and reaction will begin with addition of hydride by displacing the carbonyl group. But I am not sure will it attack both the carbonyl or only one....
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1answer
354 views

Equilibrium Constants For Phenol Tautomers

I encountered the following equilibrium constant values for the keto-enol interconversions of phenol in Organic Chemistry (Solomons, Fryhle, Snyder, 3rd Edition): I wonder what could explain the ...
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20 views

Comparison of boiling points of para-derivatives of phenol

The boiling points of four para-derivatives of phenol are: How can we compare the boiling points of p-nitrophenol and p-aminophenol? Apart from the hydroxyl group, p-nitrophenol has two oxygen atoms ...
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48 views

Will ipso substitution work in both cases of vanillic and isovanillic acids here or not?

What will be the product of the 2 reactions when bromine is taken in excess? I think ipso substitution will work here and there will be two $\ce{Br}$ substituting in both products, but in the book it ...
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125 views

How does the relative acidity of 2,3-dinitrophenol compare to that of 2,4-dinitrophenol?

I am assuming that the -I inductive effect in 2,3-dinitrophenol is stronger than in 2,4-dinitrophenol since it operates through less bonds, therefore on inductive grounds it should have a lower $\...
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4k views

Why is phenol more acidic than aniline?

I find that there are two contradicting factors at play here: 1) On removing proton, negative charge on oxygen is more stable than it is on nitrogen (because of greater electronegativity of oxygen). ...
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251 views

Why did phenol respond to Brady's reagent?

I was teaching a friend a few basic organic analysis experiments, during which I was showing him, how to get an alcohol, and took a sample of phenol. The neutral $\ce{FeCl3}$ test went fine(which i ...
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824 views

Converting phenol to para-nitrophenol via nitrosophenol

Our class 12 text book says that if we treat phenol with mixture of concentrated $\ce HNO_3$ and $\ce H_2SO_4$, instead of nitration, the ring is oxidized to quinone. So, the book proposes that we ...
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2k views

What exactly happens at the critical solution temperature of a phenol water system?

What makes phenol that was turbid go clear beyond the critical solution temperature? We say beyond the critical solution temperature the constituents become soluble. What is the reaction or the exact ...