46
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Why does lemon juice reduce the "fish" odor of sea food — specifically fish?
There are two cases, both related to acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice.
Fish, especially sea fish, naturally contain trimethylamine-N-oxide $\...
- 39.5k
21
votes
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Does nitrogen inversion affect the basicity of amines?
Background
Amine basicity correlates with, among other things, the hybridization of the nitrogen orbital that is holding the lone pair of electrons. The less s-character in this orbital, the more ...
- 84.2k
21
votes
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Selective nitro reduction of poly nitro compounds
Is there any way to predict which nitro group will be reduced
After having gone through three pages of Google Scholar and reading several research papers looking for an answer, there is definitely no ...
- 9,688
21
votes
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Can an amide nitrogen be a hydrogen bond acceptor?
If I understood you correctly, you are talking about the peptide bond nitrogens ($\ce{R-C(=O)-\color{red}{N}H-R}$). This is, reduced to its significant chemical functional group an amide, more ...
- 67.3k
21
votes
What is this fluorinated organic substance?
The name of the compound is 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (CAS #: 140681-55-6), which is commonly known as Selectfluor, a trademark of Air Products ...
- 39.5k
18
votes
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Does aniline react with diazonium ions at C or N?
This is a really interesting question and the answer is that the reaction of benzenediazonium chloride with aniline is a bit different to most of the reactions of benzenediazonium salts in that the ...
- 21.6k
18
votes
Does aniline react with diazonium ions at C or N?
In general, for anilines reaction at nitrogen is kinetically faster than reaction at carbon. However, the C-substituted product is usually more stable than the N-substituted product, so can prevail ...
- 71.1k
17
votes
Usage of ammine vs amine in nomenclature
(Will do more research into ammines come February.)
Premise
Ammonia is spelled with two 'm's. The more natural derivative of the word in a linguistic sense would also have the same number 'm's. Thus ...
- 7,021
14
votes
What causes rapid nitrogen inversion?
In the second row of the periodic table, elements have relatively small differences between the size their $\mathrm s$- and $\mathrm p$-orbitals. Therefore, the orbitals of $\ce{NR3}$ can go from $\...
- 3,274
14
votes
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What is this fluorinated organic substance?
That is generally known as Selectfluor, a source of electrophilic fluorine. The zig-zag line is a 2-D representation of the third ethylene $\ce{-CH2-CH_{2} -}$ unit that links the two nitrogens. more ...
- 21.6k
13
votes
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The mechanism of demethylation of a quaternary ammonium
As you point out, the tert-butyl group wants to remain in an equatorial position, else both the tert-butyl group and the trimethylammonium group end up being axial which is disfavoured for two bulky ...
- 17.1k
12
votes
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Can a cyclic amine form an amide?
The heterocycle in this question is indole and is aromatic. This means that the N lone pair is delocalised and not readily available for nucleophilic attack. Think of it as similar in reactivity to a ...
- 21.6k
11
votes
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11
votes
Byproducts of LiAlH4 reduction of amides
Organic chemistry textbooks I flipped through usually don't focus on by-products, only noting that LAH ($\ce{LiAlH4}$) in dry solvent (THF, diethylether) is necessary for reduction, but when one ...
- 37.4k
11
votes
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Is steric inhibition of resonance or steric inhibition of protonation dominant in o-toluidine?
The reason for the decreased basicity is essentially the ortho-effect as outlined here: Ortho-effect in substituted aromatic acids and bases.
Your question on the other hand asks about a seeming ...
- 43.8k
11
votes
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Hoffman broamide degradation but with alkoxide as base instead of NaOH
This answer is wrong, the answer should be the carbamate 4.
The reaction intermediate is the isocyanate which is captured by MeOH to give the carbamate (std Hofmann mechanism below from ...
- 21.6k
10
votes
Identify two amines
$\ce{Fc}$ stands for ferrocenyl.
So the first compound is an amide of ferrocenecarboxylic acid and tetramethylene diamine, and the second compound is p-ferrocenyl aniline.
- 7,142
10
votes
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Formamide and Hoffmann Bromamide Reaction
I have spent a lot of hours to find the evidence to support OP's idea of formamide may undergoes Hoffmann degradation reaction, but I can't find any. However, I find at least one publication, which ...
- 39.5k
10
votes
Accepted
Do amines or alcohols have stronger intermolecular hydrogen bonds?
The boiling point of non-ionic compounds are highly depend on their H-bonding abilities. For example, boiling point of water (molar mass: $\pu{18.02 g/mol}$) is $\pu{100 ^\circ C}$ at $\pu{1 atm}$ ...
- 39.5k
10
votes
Do amines or alcohols have stronger intermolecular hydrogen bonds?
Mathew Mahindaratne has provided analysis based on experimental values of the boiling points of the two compounds. I would like to offer a different view using bonding analysis.
Before I begin ...
- 10.2k
10
votes
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Ritalin/Concerta/Methylphenidate is an amphetamine?
Firstly, I'll mention that I'm not an expert on psychoactive drugs and their classifications; this is just based on my understanding of the situation as a chemist.
As far as chemical structures go, ...
- 71.1k
9
votes
Accepted
What is the pKa of methylamine
Both sources are correct. However, they are referring to two different $\mathrm{p}K_\mathrm{a}$ values.
$$\ce{H3C-NH3+ <=>[$K_\mathrm{a1}$] H3C-NH2 + H+ <=>[$K_\mathrm{a2}$] H3C-NH- + 2 H+...
- 67.3k
9
votes
What are the products of the reaction between methanamine and nitrous acid?
No chance to get alkenes from methanamine because there's no $\beta$-hydrogen for E2 elimination. And E1 elimination isn't going to work because you're not going to generate a methyl cation from the ...
- 17.3k
9
votes
Selectivity of diazo-coupling with p-amino phenol
I think the right way to approach this question isn't "we don't know the product, let's try to reason it out from first principles"; rather it should be more like "we found that this is the product ...
- 71.1k
9
votes
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Regioselectivity in coupling reactions of α-naphthol
The product at the para-position is more stable as it allows the compound to exist in the quinoid form, rather than only in the benzoid form:
This is important as in your case, if the substituent $\...
- 6,218
9
votes
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Comparing the basicity of heterocyclic amines
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 ...
- 6,925
8
votes
Accepted
Why is tetramethylammonium hydroxide a stronger base than tri- or dimethyl amine?
Between 1 and 2, 2 is more basic as the 3 methyl groups would produce a +I effect resulting in better availability of the lone pair than in option 2.
I agree that more methyl groups would result in a ...
- 18.7k
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