Questions tagged [heterocyclic-compounds]
For questions concerning compounds possessing rings with two or more different types of atoms.
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Is the 4H-Pyran Cation aromatic?
I guess I'm just trying to understand what "cyclic resonance" really means, from all the examples I've come across its always a cyclic system where the pi-electrons go all around the ...
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How is nitrogen the most powerful electron donor in aromatic rings?
In Clayden, page 735, Aromatic Heterocycles 1:Reactions:
The other simple five-membered heterocycles are furan, with an oxygen atom instead of nitrogen, and thiophene, with a sulfur atom. They also ...
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Rule for which heterocycles are stable?
In medicinal chemistry, is there a rule for which aromatic heterocycles are stable?
I've heard that heterocycles with 3+ adjacent nitrogens for example are unstable. However looking in ChEMBL at the ...
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Acidity of metronidazole
Metronidazole has two $\mathrm{p}K_\mathrm{a}$ values: $2.57$ and $15.42.$ The basic group is the imidazole moiety. Does metronidazole have acidic groups?
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Mechanism of ring expansion of epoxide
The below transformation is from
J. Am. Chem. Soc. 1990, 112, 14, 5583–5601
What does the treatment with lithium anion of ethoxyacetylene in the presence of the lewis acid do to epoxides? How does ...
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Degradation of 4-MeO-Tetrahydrocarbazole
I recently synthesized 4-Methoxy-Tetrahydroxarbazole from 4-MeO-Phenylhydrazine and Cyclohexanone. The product had a off-white color directly after synthesis but was brown after standing over night at ...
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How does a pyrrole react with its C2?
First of all, thank you for reading my question. There is a mechanism I read where the pyrrole reacts with its C2 but I can't draw the arrows so I don't know if I am correct to think that :
the ester:...
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Understanding Hybridisation in Cyclic Compounds
I had a doubt while solving this problem.
At first glance of these compounds, I felt that all of them have sp3 hybridisation (for nitrogen), since all of them had 3 bonded pairs and 1 lone pair around ...
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Boiling point of 2-methylpyridine is less than that of 3-methylpyridine? [closed]
As I was reading about physical properties of pyridines and substituted pyridines, I came across this:
2-methylpyridine boils at 129°C while 3-methylpyridine boils at 15° higher than 2-methylpyridine
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Stability of hexazine
I read about a hypothetical compound called hexazine on Wikenigma. It's a 6-membered ring all of whose atoms are nitrogen and they form alternate single and double bonds just similar to benzene. But ...
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Comprehensive Functional-Group-Priority Table for IUPAC Nomenclature
I can't seem to find a source for a comprehensive list of FG-priorities. I also am not aware of any system to determine the priority for more uncommon FGs.
One of the two would be really helpful if ...
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synthetic procedure for 1,3,4 thiadiazole from acylhydrazide [closed]
I wanted to synthesize 1,3,4 thiadiazole-2- thiol substituted to benzoic acid the reaction has to happen in such a way that the "acid hydrazide" group of benzoic acid hydrazide has to ...
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Mechanism for synthesis of benzofuran
Would someone be able to help me with the mechanism for the synthesis of benzofuran from salicyladehyde (taken from https://en.wikipedia.org/wiki/Benzofuran)? I have got as far as the decarboxylation ...
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Mechanism of Grignard reaction with 2-(thiiran-2-yl)oxirane
What will be the final major product?
The answer is 2-(methoxymethyl)-3-(substituted methyl)thiirane:
I think $\ce{R}$ of $\ce{RMgX}$ attacks thiirane ring because negative charge on sulfur is more ...
4
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Is 2-pyrone an aromatic compound?
I was told by my professor that α-pyrone is not an aromatic compound, but I count two π-electrons as well as one of the lone pairs on oxygen giving six total which would be one of Hückel's $4n + 2$ ...
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