Questions tagged [amines]

For questions about amines - organic compounds with a basic nitrogen with a lone pair, also occasionally referred to as derivatives of ammonia. Not to be confused with amides, for which the tag [carbonyl-compounds] is to be used.

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60
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6answers
46k views

Ortho-effect in substituted aromatic acids and bases

When comparing o,m,p-toluidine basicities, the ortho effect is believed to explain why o-toluidine is weaker. But when comparing o,m,p-toluic acid basicities, the ortho effect is stated as a reason ...
26
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1answer
4k views

Why does lemon juice reduce the “fish” odor of sea food — specifically fish?

In studying about amines, I read that lemon juice is also used to wash fish because it reacts with the amines on and in the fish to convert the amines to its salt, just reducing the "fishy smell". I ...
23
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1answer
20k views

Is the ammonium substituent (-NH3+) really meta-directing in electrophilic substitution?

If we make a resonance structure for the anilinium ion, with positive charge at either the ortho or the para position, we get a pentavalent nitrogen, which is not possible. So, how is the $\ce{-NH3+}$ ...
21
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4answers
6k views

Why do Organolithium or Grignard reagents act as nucleophiles and not as bases with aldehydes and ketones

I've read entire Chapter 14: Organometallic Compounds of Francis Carey's "Organic Chemistry" but I still didn't get an answer to my question. Quote from the book: Because of their basicity ...
20
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2answers
9k views

How to rationalise the resonance structures and hybridisation of the nitrogen in a conjugated amine?

I was given the first structure, and then drew the other 5 resonance structures: First of all, are they correct? ChemBioDraw had some complaints, but as far as I can see there's the same number of ...
20
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2answers
5k views

Usage of ammine vs amine in nomenclature

In the nomenclature of complex salts we use ammine for NH3 instead of amine. I thought this was to differentiate between ammine ligand and amine in organic ligand (like en). However, Wikipedia ...
17
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3answers
8k views

Selective nitro reduction of poly nitro compounds

Is there any way through which I could selectively reduce one $\ce{NO2}$ group from a dinitro- or trinitro- compound to an amine. I was reading Solomons and Frhyle and it says that m-dinitrobenzene ...
17
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3answers
3k views

Does nitrogen inversion affect the basicity of amines?

If I were to compare the basic strength of 1-azabicyclo[2.2.1]heptane and triethylamine: Can I say that 1-azabicyclo[2.2.1]heptane is more basic than triethylamine because the lone pair of electrons ...
16
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2answers
2k views

By what reaction does (–)-sparteine decompose in ambient conditions?

In its pure form (–)-sparteine is an only-slightly-yellow clear, viscous liquid. Yet, after only a week of being kept in dry, normal atmosphere (in a round bottom flask covered by a septa), some of it ...
14
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2answers
7k views

Can an amide nitrogen be a hydrogen bond acceptor?

Can $\ce{N}$ (i.e. main chain $\ce{NH}$s of recognised residues in a peptide or protein) be a hydrogen bond acceptor? It is a well known fact that the main chain $\ce{NH}$s can be a hydrogen bond ...
13
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2answers
2k views

Does aniline react with diazonium ions at C or N?

In the azo coupling of aniline with benzenediazonium cation, I thought of two possible products 1 and 2 that could be formed. However, I can't work out which will be preferred. What would be the major ...
13
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3answers
269 views

Mechanism for Amino-Imidazole Ring Fission

A reaction I've tried several times in the past is the hydrogenation of nitroimidazole derivative shown below. The amino product is extremely unstable and rapidly decomposes. This instability is ...
11
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4answers
43k views

How do you create primary amines from alcohols?

By a primary amine I mean a compound where the hydroxyl group of the corresponding alcohol is replaced with an amine group.
11
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3answers
2k views

Reduction of α,β-unsaturated nitro compounds

Would it be possible to reduce a α,β-unsaturated nitro compound to a saturated amine using for example $\ce{NaBH4}$? I know these kind of compounds will be reduced by hydrogenation using a $\ce{Pt/C}$ ...
11
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1answer
519 views

Formamide and Hoffmann Bromamide Reaction

I encountered a problem to identify the compound which does not give Hoffmann bromamide degradation reaction. One of the options was formamide, and it was given as the answer. Why can't formamide ...
11
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2answers
281 views

Dissolving metal reductions

Could reduction of an organic compound by reacting it with sodium dissolved in $\ce{NH3}$ still proceed if a metal such as aluminium were used instead of sodium? I'm not sure about the aluminium amine ...
10
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2answers
6k views

What are the products of the reaction between methanamine and nitrous acid?

What are the products of the reaction between methanamine and nitrous acid? I'm finding this particular reaction very problematic. Here's why: My teacher tells me that methanamine, when treated with ...
10
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1answer
20k views

Mechanism for formation of amide by reaction of amine with ester

This is the mechanism given in my lecture handout: I have a problem with the third species along. Surely the negatively charged oxygen would protonate before the other oxygen would. Also, why does ...
10
votes
1answer
250 views

What is the preferred IUPAC name of hexamethyldisilazane?

Hexamethyldisilazane (HMDS, $\ce{(SiMe3)2NH}$) and its conjugate base hexamethyldisilazide (as the Li/Na/K salt) find wide use in organic chemistry. In my quest to only use preferred IUPAC names in ...
10
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1answer
456 views

The appliance of LAB in amide reduction

Lithium aminoborohydride is a versatile reducing agent. In the scheme below, I don't understand how does unhindered LAB afford an alcohol in the reduction of amides while a hindered LAB affords an ...
8
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1answer
504 views

Why are triamino compounds so rare?

I was doing a reaxys substructure search for the compound shown on the left below, with the 3 amines on 1 carbon. However, the closest I found were all trinitro compounds like on the right. I would ...
8
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1answer
194 views

Hydrogenolysis of benzylic C-N bond

Why does N,N-dimethyl-1-phenylmethanamine (the left molecule in the picture) undergo hydrogenolysis of the C–N bond readily while 2-methyl-1,2,3,4-tetrahydroisoquinoline (right) doesn't react at all?
8
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1answer
278 views

What happens in the attempted diazotisation of 1,2-diaminobenzene?

Usually, $\ce{NaNO2}$ and $\ce{HCl}$ are the reagents used to generate an aryldiazonium chloride from an aniline. However, in this compound there are two amine groups adjacent to each other, so it ...
8
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1answer
3k views

Reaction mechanism of imine reduction to amine using an aluminium amalgam

I can not find any good resources on the Internet except for some shady drug syntheses. I was hoping that someone could provide me with some more educational information. I'm interested in imine-...
7
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3answers
14k views

Why amino acids (Zwitterion) become either negative or positive at low and high pH solutions?

The amino acids are Zwitterions. In neutral pH, an Amino acid's amino group has a postive charge and Carboxyl group has negative charge. They cancel each others charge thanks to the $Hydrogen$ that's ...
7
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2answers
686 views

Can a cyclic amine form an amide?

This is a question from the Cambridge International Examinations October/November 2017 (pdf from papers.gceguide.com, pdf via the Wayback Machine). I need to understand why the secondary amine in the ...
7
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1answer
1k views

The mechanism of demethylation of a quaternary ammonium

The problem is such: I know that the t-Bu locks the ring in equatorial position as I have drawn out: Could someone please point me in the right direction as how I can get rid of a Me in the NMe3+ ...
7
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1answer
2k views

What causes rapid nitrogen inversion?

When I asked my teacher whether a nitrogen bonded to 3 unique groups counted as a chiral center, they said that it did not because nitrogen undergoes rapid inversion at room temperature. What causes ...
7
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2answers
679 views

How do amines react with flue gases to absorb CO₂?

I'm reading this article about carbon capture from the combustion of fossil fuels. In this article, it says that amines are used as a chemical absorbent to capture the $\ce{CO2}$ from the exhaust of ...
7
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2answers
6k views

Is steric inhibition of resonance or steric inhibition of protonation dominant in o-toluidine?

I wish to know which effect out of steric inhibition of resonance (SIR) or steric inhibition of protonation (SIP) is dominant over the other when comparing basicities of o-toluidine and aniline: ...
6
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2answers
472 views

Identify two amines

I was reading a random text about the surface chemistry of YBaCuO superconductors. In the text, there was a table. The table had a list of several chemical compounds, including these two: Alkyl Amine:...
6
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2answers
5k views

Amine Nomenclature – When to use “N”

I'm currenty wondering what the correct naming scheme for the following molecule would be: Is this called "2,N,N-trimethylpropan-1-amine" or "2-methyl-N,N-dimethylpropan-1-amine". In other words, do ...
6
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2answers
307 views

What are the IUPAC names for singly- and doubly-protonated piperazine?

If ammonia, $\ce{NH3}$, is protonated, it becomes ammonium: $\ce{NH4+}$. If piperidine is protonated, it becomes piperidinium: If piperazine is protonated once, what does it become? By analogy, I ...
6
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1answer
710 views

Amine addition to nitro group

What is the mechanisms of this reaction? How feasible is this reaction? Can it happen under relatively mild conditions if it is intermolecular?
6
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1answer
2k views

Is 4-nitrobenzaldehyde or 4-aminobenzaldehyde more likely to be hydrated?

Of 4-nitrobenzaldehyde and 4-aminobenzaldehyde, which has the higher $\ce{K_{eq}}$ of hydration? $\qquad \qquad$ Steric factors can likely be ignored in this problem since we are dealing with ...
6
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1answer
5k views

Product of primary amine and acid anhydride

How does an acid anhydride react with a primary amine? I thought it'll be some sort of condensation reaction, so I made the product by removing a water molecule and got a cyclic product. However, the ...
6
votes
1answer
6k views

Hydrogen bonding in alcohols vs amines

Consider an alcohol and an amine compound with roughly the same molar mass. If I understand correctly, the boiling point for the alcohol is greater for two reasons: The $\ce{O-H}$ bond is more polar ...
5
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2answers
560 views

Safety when handling cyclohexylamine in non-industrial amounts

Today I was pipetting some cyclohexylamine into smaller bottles so that I don't have to use the liter flask every time I need a little bit of catalyst or plasticizer. I pipetted several 10-20 mL ...
5
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1answer
3k views

What is the pKa of methylamine

I completed a practice (not for marks) assignment for an organic chemistry course, and one of the questions asked for the pKa of methylamine. I looked on PubChem, and it gave a result of $10.6$. ...
5
votes
2answers
237 views

Predicting product of amine elimination

From section 'Nitrogen Containing Compounds' I spent quite a lot of time here but could not figure out the answer. It's not mentioned in my school text book either. The solution given in my book is: ...
5
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1answer
2k views

Nomenclature of benzene derivatives with two functional groups

In several places, I have seen that while naming benzene derivatives, no priority for substituents is followed. For example, I've seen both 2-hydroxyaniline and 2-aminophenol being used. Is there an ...
5
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1answer
2k views

Why is tetramethylammonium hydroxide a stronger base than tri- or dimethyl amine?

Of the following, which compound is the most basic?? $\ce{Me3N}$ $\ce{Me2NH}$ $\ce{Me4NOH}$ $\ce{NaOH}$ Between 1 and 2, 1 is more basic as the 3 methyl groups would produce a +I ...
5
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3answers
2k views

Why does the -OH group in β-naphthol direct the incoming diazonium salt towards the ortho position? [duplicate]

In the following reactions, the major product W is I was doing this question which asks me the product of a diazotisation coupling reaction between diazonium chloride and β-naphthol. I know ...
5
votes
1answer
114 views

How to designate the position of an amine substituent in an alkyl-chain?

Why is 1-phenylethanamine named like it is using IUPAC rules? Why isn't it 1-phenylethan-1-amine? I thought you had to designate where the amine group would be? I.e. the first position on the ethane-...
5
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2answers
7k views

In aminobenzoic acid, do we have three different pKa's?

In para-aminobenzoic acid, how can I know whether the amino group loses a proton or not when $\mathrm{pH}$ exceeds $8.5$? I have only found two values for $\mathrm{p}K_\mathrm{a}$ but I never found ...
5
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2answers
542 views

Reduction of 1,4-benzoquinone in the synthesis of 1,5-diazocane

Synthesize 1,5-diazocane using only benzene as a source of carbon atoms, and ammonia as the only source of nitrogen atoms. My attempt: Noticing that the target compound has split the benzene ring, ...
5
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1answer
2k views

Why are amines more soluble than ethers in water?

For example, diethyl ether ($\ce{C2H5OC2H5}$) has a limited solubility of $6.05\rm~\frac{g}{100~mL}$ water at $25\rm~^\circ C$. However, diethylamine ($\ce{(C2H5)2NH}$) is a lot more soluble in water. ...
5
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1answer
2k views

Can a Birch Reduction be done using gaseous anhydrous ammonia?

Instead of generating anhydrous ammonia as a liquid using either pressure or cryogenic freezing, I would like to avoid the hassle entirely by using anhydrous ammonia generated as a gas. Is there a way ...
5
votes
1answer
884 views

Regarding the mechanism for biological activity of tyramine, amphetamine and ephedrine

Graham Patrick explains the mechanism for the activity of tyramine, amphetamine and ephedrine in his book Introduction to Medicinal Chemistry as follows: Some amines such as tyramine , amphetamine ...
5
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1answer
189 views

Amine Inversion and Paramagnetism

In amine inversion, there is a planar $sp^2$ intermediate. The electron pair transferred from the blue lobe to the red one during the inversion. It is natural to assume, for a layman like me, that ...

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