ISSUE:

Hello Forumers..
For those who wish to improve their knowledge of the nomenclature of heterocyclic compounds, I propose a group of these molecules for you to name:





Greetings

Hello Foreros, this is a great song about the nomenclature of heterocycles, especially because of the number of rules that exist to first name them and then number them. So I will borrow number 25 from Wilbert, and I will ask the next question, how is this compound numbered?




Greetings

Hello CCV.

Your participation allows me to make a complementary request to the participants in this topic, and that is to ASK THEM to justify the name assigned to any of the molecules, for example, mentioning the reason why they choose a certain structure as a name base and, if possible, the orientation of the molecule in one of the reference axes, for the numbering of the atoms of the condensed cyclic system.
On the other hand, your participation and experience as a Biochemist that you are, in this matter, will be very useful for members.
Kind regards.

Hello Wilbert, as you point out, basing the name is ideal, but in order not to list all the rules, I will clarify molecule 25 with a scheme, or so I hope at least.


In this scheme we start from the final molecule, and the rules for Fused Systems of Heterocycles are applied; First there are only Nitrogens so the first rule of heteroatom precedence does not apply (Normally N > S > O ); Therefore, the bicycle that has the largest ring is chosen as Base, in this case the Pyridine with the pyrazole, the Pyridine ring has 6 atoms and the pyrazole ring has 5 atoms, so pyridine is the main element to name the bicycle and letters are assigned to the sides of the ring, the pyrrole instead is numbered. Pyrrole is only considered as a fusion to the parent molecule on the pyrazole side, and is assigned apostrophe numbering.

Regarding the numbering, there is what is known as the quadrant rule, and this determines the position of the substituents, as well as the positions of the hydrogens and their addition, as can be seen in the following figure:



In the quadrant rule, the horizontal should be taken as a reference, in such a way that it allows us to locate the greatest number of cycles in the first quadrant, and that subsequently gives the lowest numbering to the heteroatom.

I understand that this is not easy to digest, because it is just one example, but if someone likes puzzles, this is unlimited entertainment.

I hope it works for you

Greetings

Hello friends of the Forum:

Undoubtedly your contribution is very good CCV... and for those who wish to deepen the nomenclature of organic compounds, they have the "Blue Book" section on the IUPAC site, they can download it for free.
I had prepared a rationale for the name of Molecule 25, in response to CCV's question, I am uploading it so that with the nuances that I use, you benefit from your learning process...





Greetings

Where can I get the names of the molecules in the image?