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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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 ...
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34 votes
1 answer
33k 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 $\ce{-NH3+}$ ...
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  • 631
31 votes
3 answers
16k 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 ...
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  • 3,687
27 votes
1 answer
9k 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 ...
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25 votes
2 answers
13k 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 ...
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22 votes
4 answers
7k 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 ...
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  • 935
22 votes
2 answers
8k 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 ...
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22 votes
4 answers
5k 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 ...
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  • 7,380
18 votes
2 answers
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 ...
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  • 181
16 votes
2 answers
4k 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 ...
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16 votes
1 answer
10k 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 ...
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14 votes
4 answers
57k 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.
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14 votes
2 answers
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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 ...
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13 votes
2 answers
2k views

What is this fluorinated organic substance?

The corresponding author of the paper where this formula was published as appendix passed away. Can someone help me with identifying what is the name of this compound and why have strange zig-zag ...
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  • 267
13 votes
2 answers
12k 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: ...
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13 votes
3 answers
331 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 ...
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  • 397
11 votes
3 answers
3k 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 $\ce{Pt/C}$ ...
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  • 6,033
11 votes
1 answer
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 ...
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  • 837
11 votes
1 answer
22k 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 ...
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  • 9,436
11 votes
2 answers
606 views

What is the mechanism for iodoform test given by 2-aminoalkanes?

I found 2-aminoalkanes in the list of compounds that give positive iodoform test. I was surprised as they have no keto methyl or methyl carbinol group. Can someone help with the mechanism?
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  • 339
11 votes
2 answers
377 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 ...
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10 votes
1 answer
877 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 ...
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10 votes
1 answer
306 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 ...
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10 votes
1 answer
600 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 ...
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  • 14k
8 votes
2 answers
1k 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 ...
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  • 191
8 votes
1 answer
517 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 ...
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  • 2,168
8 votes
1 answer
234 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?
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  • 14k
8 votes
1 answer
296 views

Hoffman broamide degradation but with alkoxide as base instead of NaOH

Ans.3 I thought it would be similar to Hoffman bromide reaction, and hence the answer (1) but turns out the answer is (3), suggesting the alkoxide attacks the formed amine. But, I couldn't find any ...
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8 votes
1 answer
533 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 ...
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8 votes
1 answer
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-...
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8 votes
2 answers
12k views

Why are tertiary amines less basic than secondary and primary amines in water than when vapourised?

In gaseous state: $$\ce{(CH3)3N} > \ce{(CH3)2NH} > \ce{CH3NH2} > \ce{NH3}$$ However, when dissolved in water: $$\ce{(CH3)2NH} > \ce{CH3NH2} > \ce{(CH3)3N} > \ce{NH3}$$ My notes ...
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7 votes
2 answers
754 views

Do amines or alcohols have stronger intermolecular hydrogen bonds?

Which has stronger hydrogen bonding, $\ce{CH3OH}$ or $\ce{CH3NH2}$ I think it comes down to which has more dominance; number of hydrogens, number of lone pairs, or electronegativity.
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7 votes
3 answers
16k 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 ...
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  • 1,896
7 votes
2 answers
6k 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 ...
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  • 427
7 votes
1 answer
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+ ...
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  • 1,771
7 votes
2 answers
918 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 ...
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  • 427
7 votes
2 answers
8k 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 ...
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7 votes
3 answers
8k 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 that the ...
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7 votes
2 answers
452 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 ...
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7 votes
1 answer
13k 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 ...
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7 votes
3 answers
6k views

How can I rationalise the different basicities of cyclohexylamine, piperidine and morpholine?

Compare the basicity of the following compounds: Comparing compounds I and II Since there is no conjugated system, there is no resonance at play and we only have to discuss hyperconjucation and ...
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7 votes
1 answer
280 views

Comparing acidic strengths between benzylammonium ion and phenol

Question Compare the acidic stengths between benzylammonium ion and phenol. I first tried to remove the H+ ion from both of them and tried to compare the relative stabilities of resulting conjugate ...
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  • 1,209
7 votes
2 answers
318 views

Why does a larger bond angle correspond to greater s-character?

In trialkylamines $\ce{NR3}$, the $\ce{R}$ alkyl group attached to nitrogen increases the electronegativity of the nitrogen atom. I also found in this question that this happens due to the repulsion ...
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  • 442
6 votes
2 answers
483 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:...
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6 votes
2 answers
637 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 ...
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  • 6,033
6 votes
1 answer
245 views

Comparing the basicity of heterocyclic amines

Compare the relative basicity of the following amines. I know that the higher the electron density on the nitrogen the higher will be its basicity. So here’s my take on each option. (a)The Nitrogen ...
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  • 245
6 votes
1 answer
3k 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 ...
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6 votes
1 answer
506 views

Formation of Aniline from Chlorobenzene

My textbook says: When chlorobenzene is treated with aqueous ammonia at 473K under a pressure of 60 atmospheres in presence of cuprous oxide or cuprous chloride, aniline is formed. Notice the ...
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  • 502
6 votes
1 answer
835 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?
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  • 14k
6 votes
1 answer
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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 ...
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