# Tag Info

19

Does folic acid contain a benzyl or a phenyl group? This is the question asked in the title. At the first glance to the structure, one would say folic acid consists of phenyl function but not benzyl function because the question did not define what is the phenyl group. In reality, phenyl group $(\ce{Ph})$ is $\ce{C6H5}$. As Poutnik pointed out in the ...

16

The rate of Aromatic substitution depends upon the activity of the aromatic system, because when the collision happens the aromatic system has to donate electrons to an electrophile. In the example above you have used nitro-benzene, which is very strongly deactivated due to the $\ce{-NO2}$ group and thus the ortho and para positions are completely blocked. ...

15

During a electrophilic aromatic substitution, it is always possible to have multiple substitutions during one reaction. However, your example is not the ideal one for a discussion. As noted, Oscar Lanzi has questioned even aromatic ring of nitrobenzene is active enough to give even one $\ce{Br}$ substitution. To clear that, I have found a reliable reference: ...

10

According to this source Chemistry Libre Texts Alkynes, similar to alkenes, can be oxidized gently or strongly depending on the reaction environment. Since alkynes are less stable than alkenes, the reactions conditions can be gentler. For examples, alkynes form vicinal dicarbonyls in neutral permanganate solution. For the alkene reaction to vicinal ...

9

As I noted in a Comment that there should be no significant difference between the use of ethanol or isoamyl alcohol in the reduction of naphthalene with sodium in that both alcohols are primary. The difference lies in the conditions of the reaction. The sequence is a classic case of kinetic vs. thermodynamic conditions. The reaction conditions in the ...

9

The correct order is in fact $(\bf{d}) \gt (\bf{b}) \gt (\bf{c}) \gt (\bf{a})$, the reason for this is as follows. $(\bf{a})$ is definitely last in this order of basicity since its lone pair is delocalised by the phenyl ring. Now we need to compare the other three. We can split this into two parts, a comparison between $(\bf{d})$ and $(\bf{b})$ $(\bf{b})$ ...

9

It is complicated, as this paper from Olah et al. here shows, but this passage offers a possible explanation: With the reactive nitronium salts, the isomer distribution of the nitration of anisole shows the highest ortho/para ratio (2.7-2.4), reflecting the "early" (i.e., starting aromatic-like) nature of the transition state of highest energy. ...

9

You are completely correct - the furan derivatives you've drawn display unquestionable aromatic character, though the "strength" of their aromaticity is somewhat lower than various other prototypical organic aromatic compounds. By aromatic, the examiners really were assuming you would think benzenoid. While the latter term is more precise for the ...

8

Following are the Statement from “On Terephthalic Acid and its derivatives” By Warren De la Rue and Hugo Muller February 7, 1861: On heating, terephthalic acid sublimes without previously fusing(melting). The sublimate, which is indistinctly crystalline, has the same composition and properties as the original acid, and therefore, unlike other bibasic acids, ...

8

Naphthalene is more reactive towards electrophilic substitution reactions than benzene. On a quick glance you might think that as 10 pi electrons are delocalized on 10 carbon atoms in case of naphthalene, it should have resonance energy per bond similar to that of benzene and thus making both equally active towards electrophiles. But in practise it is ...

8

It depends on the reaction conditions. I suspect the answer the question setter wants to see is phthalic acid, but the true answer is none of these. I have found multiple references (such as this US Patent and this Org. Syn prep) that refer to the production of naphthoquinones by oxidation of naphthalenes with high valent Chromium reagents under acid ...

8

TL;DR: It is a possible but complicated reaction and you get a mixture of products but formation of haloarene is not significant in any reaction Long answer: phosphorus trichloride: form triphenyl phosphite $$\ce{3 PhOH + PCl3 → P(OPh)3 + 3 HCl}$$ (The phenol is essentially acting as a nucleophile through oxygen, attacking the phosphorus.) phosphorus ...

8

Brief explanation Hot alkaline solution of potassium permanganate oxidises a terminal alkyne according to the following process: Triple bond between the first and second carbon atoms (they are marked in the figure above) converts into two carbonyl groups $\ce{C=O}$. The resulting molecule consists of a ketone part (blue) and an aldehyde part (red). The ...

7

The problem in ortho-aminobenzoic acid is that the acidic hydrogen of carboxylic group is H-bonded with the lone pair of nitrogen in amino group. As a result it is more difficult to extract it compared to that in para-aminobenzoic acid since the H-bond must also be broken during acid-base reaction. Para-aminobenzoic acid does not have a H-bond due to the ...

7

There are three common classes of methods: Separate the components of the mixture, then detect the amounts of the substances. Use a fancy method that can identify multiple substances in a mixture (such as training a dog to smell different substances, or nuclear magnetic resonance) Use a method that detects only your substance of interest, even when in a ...

7

This can be explained by comparing the stability of the carbocations formed in Friedel-Crafts acylation and Friedel-Crafts alkylation using chloroacetylchloride. This is because the rate determining step in both reactions is the formation of the carbocation. As you can see, the acyl carbocation is resonance stabilized, whereas the carbocation formed in the ...

7

The molecule shown by the OP is cis (Z) cinnamic aldehyde - not the ordinary trans (E) cinnamaldehyde. Trans cinnamaldehyde melts at -7.5C, so is liquid at room temperature, and while the melting point of the cis wasn't available, it has been described as a yellowish liquid. The trans isomer is available from fine chemical suppliers at about 50 USD/kg, but ...

6

@Waylander has provided a concise route to the nitro compound in question. I am also in accord with his comments regarding the OP's effort and his assessment that benzene, as a starting material, is not a choice by a practicing chemist. Now that he has opened the door to a solution, I offer a more traditional approach. Classical nitration of ketoacid 7 ...

6

@user1055 answered the question pretty much. I am just going to add a complementary answer which has the abstract to the paper which @user1055 mentioned. The abstract of the paper mentions the various products of the decomposition reaction: The thermal decomposition behavior of terephthalic acid (TA) was investigated by thermogravimetry/differential thermal ...

6

Most likely chromatography. Gas chromatography is often used for detecting volatile compounds. You vaporize the sample at the inlet of a very long, thin tube (the column). The sample then gets pushed along by a carrier gas (the mobile phase). The different components of the mixture interact differently with the stationary phase inside the column and so take ...

6

No. It is because the lowest three MOs are lower in energy than the corresponding original AOs. In other words, the electrons would rather be there than belong to the separate atoms, as if they wanted the atoms to be together rather than apart. Actually, there is no "as if". These electrons are the force that brings the atoms together. That's ...

5

The lone pair of electrons will be in a $\mathrm{sp^2}$ hybridized orbital and not in a pure p-orbital. Thus, it wil be in the same plane as the molecule. Only the lone pairs which are in an orbital perpendicular to the molecular plane can take part in resonance, so those $\mathrm{sp^2}$ electrons will not be counted in Hückel's rule.

5

I already made a comment about some of what I am about to say but I will provide a partial answer. I say partially because I could not find any mechanism for the second product. However, from literature, what I found was that in acidic conditions, $\ce{KMnO4}$ will oxidize naphthalene into the first product, phthalic acid1. In basic/alkaline conditions, $\ce{... 5 No the products shouldn’t be reversed as, to put simply, acylation is preferred over alkylation. This is a conclusion based on various experimental results and there are many reasons that can be given for the same. As said in the concluding lines of this article from Chemistry Libretexts, Friedel-Crafts Acylations offer several synthetic advantages over ... 5 One possibility: the alkyne gets its$\alpha$hydrogen through formation of a hydrate. The triple bonded carbon is electrophilic with its relatively high electronegativity, with the attack occurring on the remote carbon to form a stabilized (benzylic) carbanion:$\ce{C6H5C#CH\overset{H_2O/OH^-}{<=>}C6H5\overset{-}{C}=CHOH<=>C6H5CH=CHOH}$The form ... 5 Friedel-Crafts reactions of anisole is known and the relevant acylation is performed in most academic institutions during undergraduate sophomore organic chemistry laboratories. For instance, Aluminum Chloride Catalyzed Friedel-Crafts reaction of anisole with Epoxide has been published (Ref.1). The authors have performed the reaction in various solvents ... 5 I just wanted this question not to be unanswered when the answer was itself subtly discussed in the comment section. Hence here's the part of discussion which provides some answer to this question. Of course the knowledge was borrowed and this is from @IvanNeretin . Ivan Neretin emphasizes the flexibility of answers and the social structure of education. ... 5 Phthalocyanine is flat, for example in the crystal structure (linked on PubChem) or PQR or Wikipedia As noted in the comments, PubChem uses an efficient force field (MMFF94) which does not consider aromaticity. Since the record you linked is protonated (though strangely in a cis-oid configuration, not the typical trans-oid depiction) the steric ... 4 Two factors come into play: (1) the inherent difference in resonance energy is not as great as you might think, and (2) the greater tendency for a dissociable proton to bind more tightly to an oxime function rather than a phenol function appears to counterbalance the reduced$\pi$-electron bonding difference. Less than meets the eye Suppose you were to use ... 4 With the$\ce{C=C}\$ double bond of the stilbenes as geometric reference, you may think of the phenyl rings as substitutents increasing the electron density of the former. This creates a small, locally constraint, dipole moment. Dipoles like dipoles differ from a scalar (like e.g., temperature) that they have a direction, which is why I drew little arrows ...

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