Hot answers tagged

28 votes
Accepted

Friedel–Crafts reaction of phenol

Like aniline, phenol too reacts to a very less extent during Friedel-Crafts reaction. The reason being that the oxygen atom of phenol has lone pair of electrons which coordinate with Lewis acid. ...
user avatar
18 votes
Accepted

Acidity of substituted phenols

I would appreciate learning whether such reasoning, for these two type of substituted phenols is plausible or whether furthermore solid arguments should be invoked. Your reasoning seems generally ...
user avatar
  • 81.6k
18 votes

Benzene to phenol in a single step

The reaction of benzene over $\ce{V2O5/ PtAu}$ catalyst at lower temperatures, can convert benzene to phenol with some success. See this book here Direct hydroxylation of benzene [The original ...
user avatar
  • 32.1k
16 votes

Acidity order of nitrophenols

You have correctly identified that m-nitrophenol should be the weakest acid among the isomers as the resulting anion cannot be stabilised by the $\text{-M}$ effect of nitro group owing to its meta ...
user avatar
  • 5,128
14 votes

Friedel–Crafts reaction of phenol

To add to @user223679's answer. Phenol can react via two pathways with acyl chlorides to give either esters, via O-acylation, or hydroxyarylketones, via C-acylation. However, phenol esters also ...
user avatar
  • 14.9k
14 votes

Why is meta-nitrophenol less acidic than para-nitrophenol?

The acidity of nitrophenols (or any acid for that matter) is determined by the stability of the conjugate base. In the case of m-nitrophenol and p-nitrophenol, the relative stability can be determined ...
user avatar
  • 14.9k
13 votes
Accepted

Aromatic ether to phenol reagents

The reaction is demethylation of methoxybenzene. You can do it by using an acid which has a nucleophilic counter ion. It is not actually obvious why the iodine nucleophile attacks the methyl group ...
user avatar
12 votes
Accepted

Why isn't 4-hydroxybenzoic acid formed along with salicylic acid in Kolbe's reaction?

I don't understand why two different products are formed in the same reaction using very similar bases. If the bases make a a difference, there must be a difference between them. If the anion is the ...
user avatar
11 votes

Can phenol be detected with a ceric ammonium nitrate test?

With unsubstituted phenol ($\ce{PhOH}$) dark-brown precipitation is formed: $$\ce{(NH4)2[Ce(NO3)6] + 2 PhOH -> [Ce(NO3)4(PhOH)2] + 2 NH4NO3}$$ Other phenols should produce wine-red solution as ...
user avatar
  • 34.7k
11 votes
Accepted

Reimer–Tiemann-like reaction of catechol with diiodomethane

This is not really an answer to your question, but I do not think that it is possible to answer it. From one of the many comments we learn that the reference is actually the "preparation of ...
user avatar
10 votes

Synthesis of 2-methyl-4-nitrophenol from benzene?

There is a lot of good thinking in your proposed synthetic strategy. The one major shortcoming is, as @Mithoron points out, $\ce{OH^{-}}$ is not an electrophile. We need to introduce a methyl, ...
user avatar
  • 81.6k
10 votes

Can the hydroxyl group of 4-hydroxybenzoic acid react with phosphorus pentachloride?

a phenol will not react (or react very slowly) with $\ce{PCl5}$ That's not true. Phenol and $\ce{PCl5}$ do react, producing mixture of compounds of formula $\ce{PCl_n(C6H5O)_{5-n}}$ (with $n > 1$ )...
user avatar
  • 20.6k
10 votes

Strength of hydrogen bonding in phenol or methanol

Let me answer the second question first, because the answer is so much easier: Of course the hydrogen bond strength depends among others upon the carbon oxygen is attached to. Consider phenol and ...
user avatar
  • 63.7k
10 votes
Accepted

What is the product of the chemical reaction between phenol and ferric chloride?

After doing some looking around, and going back to check what I thought I knew about coordination complexes, I think I understand why you're seeing two equations. I first recommend reading the pages ...
user avatar
  • 166
10 votes
Accepted

Phenol smell from hands

As an acidic compound, phenol started to degrade the protective layers of your skin, and partially diffused into deeper layers. This, and because of the moderate solubility in water are the reason ...
user avatar
  • 23.6k
10 votes
Accepted

Reaction of phenol and zinc dust

Ludwig Gattermann's The Practical Methods of Organic Chemistry (translated into English, 1896) has two references to reduction of aromatics with zinc dust: The first one refers to Liebigs Annalen, ...
user avatar
10 votes
Accepted

Reaction mechanism of rearrangement

The first reaction is O-alkylation of p-cresol to give a 4-methylphenyl allyl ether derivative 3. The reagent in the first box should be 1-bromo-3-methylbut-2-ene (1; see the top box in the picture), ...
user avatar
9 votes

How are phenols made?

That reaction will definitely not yield a phenol. Phenols are not usually prepared directly from benzene, but from benzene derivatives, such as toluene or chlorobenzene: Oxidation of toluene, as ...
user avatar
9 votes

Electrophilic Aromatic Substitution: Are protonated OH-groups ortho-/para- or meta-directing?

O-protonated phenols direct in meta, according to an article on that topic. As it occurs, phenols can be, depending on acid, protonated on oxygen, but also on carbon. They can even be diprotonated, ...
user avatar
  • 4,346
9 votes
Accepted

Why is picric acid more acidic than carbonic acid?

So you want to compare the acidity of different Brønsted–Lowry acids. This means ultimately you want to compare the equilibrium constants for reactions of the type $\ce{HX <=> H+ + X-}$. To do ...
user avatar
9 votes

Halogenation of Phenol

The reaction of phenol with bromine is known as bromination of phenol. Solvent has great influence on the reaction. In different solvents, different products are obtained. The action of bromine on ...
user avatar
  • 312
8 votes
Accepted

Why is a hydroxyl group more activating than a methoxy group in electrophilic aromatic substitution?

First of all we must have to note that the difference in reactivity between anisole (methoxybenzene) and phenol is small. Small enough for the undergraduate texts I own to not mention anisole ...
user avatar
  • 6,023
8 votes

Aromatic ether to phenol reagents

Boron tribromide is a standard reagent for cleaving aryl methyl ethers to the corresponding phenol. It is a general method and can be used in aromatic methyl ethers with sensitive substituents where ...
user avatar
  • 81.6k
8 votes

Why is the para product major in the nitrosation of phenol?

Ortho and para positions are activated due to the +R effect of the $\ce{-OH}$ but the preference of the para product can be explained by the mechanism. The mechanism proceeds through a dienone....
user avatar
8 votes

Gattermann-Koch Reaction with Phenol Substrates

You have outlined that the formyl chloride is generated as the reactive, electrophilic intermediate under these conditions. You are planning to perform an electrophilic aromatic substitution, but in ...
user avatar
8 votes

Between 3-chlorophenol and 3-fluorophenol, which one is more acidic?

Experimentally, the $\mathrm pK_\mathrm a$ values for 3-chlorophenol and 3-fluorophenol appear to be (perhaps unexpectedly) equivalent. The table below1 shows the measured $\mathrm p K_\mathrm a$ ...
user avatar
  • 16.7k
7 votes

Selective alkylation of carboxylic acid versus phenol

Using the haloform reaction to convert the methyl ketone 1 to the corresponding carboxylic acid 2 is a neat idea. According to an old review by R. C. Fuson and B. A. Bull, published in Chem. Rev., ...
user avatar
7 votes

Inductive vs resonance effects and the acidity of phenol

That blog post you are referencing voices very strong opinions with which one can agree or disagree. I personally love one of the comments under the blog saying I judge people by the units they use....
user avatar
  • 63.7k
7 votes
Accepted

Suggestion for a Synthesis of Paracetamol — plausible?

Your route sounds possible, yes. (Aniline is commercially available.) There would very likely be side reactions of the amide under Baeyer-Villiger conditions but nothing exceptionally out of control—...
user avatar
  • 63.7k

Only top scored, non community-wiki answers of a minimum length are eligible