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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3answers
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Acidities of amines and carboxylic acids

I have been told that the first of the two acids is the stronger acid. According to this person,deprotonation for both occur at the nitrogen.The resulting conjugate bases include,respectively a ...
2
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1answer
3k views

What happens to the amino acid when it is in a solution with the pH of its isoelectric point? (zwitterions)

I am learning about zwitterions and am confused about the following: From what I understand, when amino acids are in their solid form, they exist as zwitterions which is why they have such a high ...
2
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1answer
17k views

Amine group - electron donating or withdrawing group?

Is the amine group a donating or withdrawing group? I think it depends on resonance. If the amine group can participate in resonance, the amine group is inductively donating. Resonance depictions ...
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1answer
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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 ...
5
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1answer
493 views

Deamination of Spermidine?

I was making a solution of spermidine, and noticed that Sigma Aldrich warns that spermidine solutions deaminate over time. I tried to think of how that would happen, and made a diagram: Assuming some ...
2
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1answer
1k views

Why is the deprotonated form of dopamine more reactive than the protonated/neutral form of dopamine?

See this (from the Wikipedia article on dopamine): Dopamine, like most amines, is an organic base. At neutral or acidic pH levels it is generally protonated. The protonated form is highly water-...
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 ...
2
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2answers
11k views

Field Effect and it's effect on basicity on amines

What is the order of basicity between $\ce{Me2NH}$, $\ce{Me3N}$, $\ce{MeNH2}$ in a protic solvent. It has something to do with field effect which I could not understand and could not find anywhere. ...
4
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1answer
2k views

Amine inversion and effect on basicity

What is amine inversion, and how does it affect basicity? For instance, why is $\ce{Et3N}$ less basic than (2.2.2.)cyclohexyl-amine despite the $+I$ from ethyl groups? The answer here is (c).
4
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2answers
3k views

Are all amides also amines?

I watched a Khan academy video on organic chemistry functional groups. It mentioned the amine and amide groups. From what I see, an amide is an amine with a carbonyl group. However, the internet says ...
3
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1answer
826 views

Doesn't methyl amine give carbylamine test?

A compound $\ce X$ of formula $\ce{C2H5NO2}$ on treatment with $\ce {HNO2}(\ce{NaNO2}+\ce{HCl})$ gives off an inactive gas $\ce Y$ and forms $\ce Z$. When heated with soda lime, $\ce X$ gives $\ce{A(...
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3answers
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Intermolecular forces in secondary amines compared to primary amines

Secondary amines form hydrogen bonds, but having nitrogen in the middle of the chain rather than at the end makes the permanent dipole on the molecule slightly less. The lower boiling point is due to ...
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 ...
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-...
4
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0answers
264 views

What is the average chain length of a glutaraldehyde crosslink between primary amines?

Imagine I'm performing a primary amine to primary amine (i.e. PA to PA) crosslinking reaction at $37~^{\circ}\mathrm{C}$ in phosphate-buffered saline (pH $\approx 7.4$) with glutaraldehyde drawn from ...
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 ...
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 ...
2
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0answers
261 views

Primary amine versus phosphoramidate reactivity with succinate esters

I have posted two reactions below. The top reaction is well known and occurs readily and near quantitatively (e.g. in protein modification), while the bottom reaction to my knowledge does not exist in ...
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 ...
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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.
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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 ...
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2answers
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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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