Electrophilic substitution occurs at C-2 if the C-3 position is occupied, and electrophilic substitution if they are both occupied C-6 bit3.1. 1 Protonation: Indole is a very weak base with pKa -3.5. Even in water (pH = 7), the nitrogen atom of indole is easily protonated, yielding 1H-indolium cations.
Why does the electrophilic substitution of indole occur at C3?
The most reactive position in indole The ring is the third carbon. This is more reactive for electrophilic substitution reactions, even more reactive than benzene. Vilsmeier-Haack formylation can occur at the third position of the indole. …
What does electrophilic attack mean?
Electrophilic substitution reactions are chemical reactions in which Electrophiles replace functional groups in compounds, usually but not always hydrogen atoms. … some aliphatic compounds can also undergo electrophilic substitution.
At which position of anthracene is electrophilic attack most stable and why?
In most other reactions of anthracene, the central ring is also the target because it is the most reactive.Electrophilic substitution occurs at The « 9 » and « 10 » positions of the center ringand anthracene is easily oxidized to produce anthraquinone, C14H8O2 (below).
Where does the nucleophilic substitution of quinoline occur?
Quinolines also undergo nucleophilic substitution reactions.Replacement happens at C-2 (at C-4 if C-2 is blocked).
Electrophilic substitution of pyridine
36 related questions found
What heteroatoms are present in furan?
Furans, any of heterocyclic aromatic organic compounds characterized by a ring structure consisting of a Oxygen atom and four carbon atoms. The simplest member of the furan family is furan itself, a colorless, volatile, and somewhat toxic liquid with a boiling point of 31.36° C (88.45° F).
Which position in anthracene is more reactive?
median or 9,10 It is the most active in anthracene. Additions and substitutions usually occur at these positions; during oxidation, 9,10-anthraquinone is formed This is because this reaction leaves the two most stable benzene rings in the anthracene structure (resonance energy 72 kcal/mole) .
Why is benzene more stable than naphthalene?
in electronic structure
Both are aromatic, both have delocalized electrons, but Naphthalene has more pi bonds So more resonance structures and more delocalization, so overall it has to be more stable.
Which is more reactive, naphthalene or anthracene?
The resonance energy of anthracene is lower than that of naphthalene. Therefore, Anthracene is more reactive than naphthalene. As the number of fused aromatic rings increases, the resonance energy per ring decreases and the compound becomes more reactive.
What are some examples of electrophilia?
Examples of electrophiles are Hydronium ion (H3O+, from Bronsted acid), boron trifluoride (BF3), aluminum chloride (AlCl3), and halogen molecules fluorine (F2), chlorine (Cl2), bromine (Br2) and iodine (I2). Compare nucleophiles.
Is H+ an electrophile?
H+ is one of them Electrophiles only Guaranteed to be an electrophile. It has no electrons, so of course it can only accept electrons. Therefore, it must be a Lewis acid or an electrophile.
Where do nucleophiles attack?
Nucleophiles can attack from top or bottom and thus produce a racemic product. It is important to use protic solvents, water and alcohols as aprotic solvents may attack intermediates and produce unwanted products.
What is the pH of indole?
We show that under conditions that allow indole production, cells maintain their cytoplasmic pH at 7.2. In contrast, under conditions that do not produce indole, the cytoplasmic pH is close to 7.8.
Is indole toxic?
Indole is a derivative of the amino acid tryptophan, which is toxic signaling molecule, can inhibit bacterial growth. To overcome indole-induced toxicity, many bacteria have developed enzymatic defense systems to convert indole to nontoxic, water-insoluble indigo.
What is indole used for?
Indole-3-carbinol is a substance found in vegetables such as broccoli, Brussels sprouts, cabbage, kale, cauliflower, collard greens, mustard greens, turnips, and rutabagas. It can also be produced in a laboratory. Indole-3-carbinol is used for Prevent breast, colon and other types of cancer.
What is the shortest bond in Philippine and why?
or test.In the above structure, we can see The bond between carbon 9 and carbon 10 is the shortest.
Which structure of benzene is more stable?
The treatment of benzene ring stabilization involves two quite different problems. The first is to explain why all the single-ring structures CnHn, Benzene (n = 6) is currently the most stable.
Which is more stable, azulene or naphthalene?
It is not as stable as naphthaleneheated to above 350o in the absence of air, it isomerizes quantitatively: Azulene is significantly polar, negative for five-membered rings and positive for seven-membered rings.
What is the chemical formula of anthracene?
Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) with the formula C14H10, consisting of three fused benzene rings. It is a component of coal tar.
Is anthracene acidic or basic?
Anthracene does not react with coal tar, so anthracene acidic, alkalinewhile the amphoteric can be neglected, as this would react with different compositions of coal tar and anthracene.
Why is the alpha position of naphthalene more reactive?
The electrophilic substitution reaction in naphthalene is very similar to the benzene reaction.alpha Position is more stable than beta position. The carbocation formed at the α position after electrophile attack is more stable than the second position due to its resonance.
Is pyridine acidic or basic?
The nitrogen center of pyridine has a pair of basic lone electrons.This lone pair does not overlap the aromatic π-system ring, so the pyridine is basicwith chemical properties similar to tertiary amines.
Is thiophene acidic or basic?
Pyrrole, furan or thiophene don’t have any bond to electrons to release freely, that’s why they shouldn’t release basicbut organic chemistry lecturers say they are basic because they react with hydrochloric acid to form salts.
Where is thiophene found?
it occurs with benzene in coal tar, its source was first isolated in 1883. Today, thiophenes are prepared commercially from butane or butene and sulfur or sulfur dioxide. Certain thiophene derivatives occur in the form of plant pigments and other natural products.