Podcast
Questions and Answers
What are the three parts of the name for heterocyclic aromatic compounds?
What are the three parts of the name for heterocyclic aromatic compounds?
Which prefix indicates the presence of sulfur in heterocyclic compounds?
Which prefix indicates the presence of sulfur in heterocyclic compounds?
In the nomenclature order of heteroatoms, which heteroatom has the lowest priority?
In the nomenclature order of heteroatoms, which heteroatom has the lowest priority?
Which of the following correctly describes the role of the stem in the nomenclature?
Which of the following correctly describes the role of the stem in the nomenclature?
Signup and view all the answers
What information does the suffix of a heterocyclic aromatic compound name convey?
What information does the suffix of a heterocyclic aromatic compound name convey?
Signup and view all the answers
Which prefix is used for oxygen in the nomenclature of heterocycles?
Which prefix is used for oxygen in the nomenclature of heterocycles?
Signup and view all the answers
When two or more heteroatoms of the same type are present, which prefix should be used?
When two or more heteroatoms of the same type are present, which prefix should be used?
Signup and view all the answers
What is the primary purpose of using prefixes in the nomenclature of heterocycles?
What is the primary purpose of using prefixes in the nomenclature of heterocycles?
Signup and view all the answers
What prefix is used to indicate complete saturation in nomenclature?
What prefix is used to indicate complete saturation in nomenclature?
Signup and view all the answers
How should monocycles with one heteroatom be numbered?
How should monocycles with one heteroatom be numbered?
Signup and view all the answers
What prefixes are used to indicate two or more similar atoms in a monotcycle?
What prefixes are used to indicate two or more similar atoms in a monotcycle?
Signup and view all the answers
When there are multiple heteroatoms in a ring, how is the numbering determined?
When there are multiple heteroatoms in a ring, how is the numbering determined?
Signup and view all the answers
What is retained in the nomenclature of many fused heterocycles?
What is retained in the nomenclature of many fused heterocycles?
Signup and view all the answers
When naming a carbocycle fused with a heterocycle, what is the parent name?
When naming a carbocycle fused with a heterocycle, what is the parent name?
Signup and view all the answers
Which order of preference is followed for heteroatoms in the naming process?
Which order of preference is followed for heteroatoms in the naming process?
Signup and view all the answers
What is a characteristic of fused heterocycles in IUPAC nomenclature?
What is a characteristic of fused heterocycles in IUPAC nomenclature?
Signup and view all the answers
What is the first preference when selecting the parent ring?
What is the first preference when selecting the parent ring?
Signup and view all the answers
If a ring contains no Nitrogen, which characteristic dictates its status as a parent ring?
If a ring contains no Nitrogen, which characteristic dictates its status as a parent ring?
Signup and view all the answers
In what situation is the largest ring size selected as the parent ring?
In what situation is the largest ring size selected as the parent ring?
Signup and view all the answers
What is the first step in naming a fused benzene system?
What is the first step in naming a fused benzene system?
Signup and view all the answers
How is the side of fusion with the parent ring numbered?
How is the side of fusion with the parent ring numbered?
Signup and view all the answers
How is the side fusion of the parent ring indicated in naming?
How is the side fusion of the parent ring indicated in naming?
Signup and view all the answers
Which aspect defines the prefix ring's side of fusion?
Which aspect defines the prefix ring's side of fusion?
Signup and view all the answers
When selecting a parent name based on trivial names, what is the key determining factor?
When selecting a parent name based on trivial names, what is the key determining factor?
Signup and view all the answers
Which of the following describes how to orient a fused system for numbering?
Which of the following describes how to orient a fused system for numbering?
Signup and view all the answers
In the selection process, what is considered if multiple incorporated rings exist?
In the selection process, what is considered if multiple incorporated rings exist?
Signup and view all the answers
What is the significance of hetroatoms in the numbering process?
What is the significance of hetroatoms in the numbering process?
Signup and view all the answers
What is the significance of the order of writing the numbers in the square brackets for fusion?
What is the significance of the order of writing the numbers in the square brackets for fusion?
Signup and view all the answers
Which parent name is typically given to a polycyclic structure?
Which parent name is typically given to a polycyclic structure?
Signup and view all the answers
When numbering a complete fused system, what direction is preferred?
When numbering a complete fused system, what direction is preferred?
Signup and view all the answers
Which is a requirement for the IUPAC naming of fused heterocycles?
Which is a requirement for the IUPAC naming of fused heterocycles?
Signup and view all the answers
Which of the following is NOT a part of the IUPAC naming rules for fused systems?
Which of the following is NOT a part of the IUPAC naming rules for fused systems?
Signup and view all the answers
Study Notes
Heterocyclic Aromatic Compounds: Nomenclature
-
Intended Learning Outcomes (ILOs):
- Students will be able to identify different heterocyclic ring systems.
- Students will be able to write nomenclature for monocyclic and fused heterocyclic rings.
- Students will be able to use this knowledge to name any heterocyclic medicinal compound.
Nomenclature of Monocycles
- Structure: Names consist of three parts: prefix, stem, suffix.
- Prefix: Indicates the type and position of heteroatoms (e.g., di, tri for multiple same heteroatoms). Order of priority for heteroatoms: O > S > Se > N > P > Si > B > Hg.
- Stem: Determines the ring size (3-10 members). Specific suffixes for each ring size are assigned (e.g., 3-membered ring = ir).
-
Suffix: Determines the saturation. Suffixes for saturated and unsaturated rings, and saturated rings with nitrogen are provided.
- Adding "hydro" to the suffix indicates complete saturation.
-
Numbering:
- Monocycles with one heteroatom are numbered starting at the heteroatom.
- Monocycles with multiple similar heteroatoms use prefixes (e.g., di, tri..)
- Monocycles with multiple different heteroatoms number according to priority, assigning the lowest possible numbers to heteroatoms.
Table I: Heteroatom Priority
- A table lists heteroatoms and their prefixes in order of priority.
Table II: Ring Size and Suffixes
- A table shows the ring size and associated suffix for saturated and unsaturated rings.
Nomenclature of Fused Heterocycles
-
Carbocycle fused with heterocyclic system:
- The parent name is the heterocyclic ring name (at the end).
- The fused benzene ring is "benzo" (at the beginning).
- The side of fusion is noted with letters (a,b...) between the fused name and parent name.
- The fused system numbering is done to assign positions to saturation or substitutions.
- The greatest number of rings are placed horizontally
- Other rings above the horizontal row
- Numbering begins next to the fusion point,
- Proceeding in clockwise direction,
- Adding the letters (a,b,c...)
-
Heterocycle fused to another heterocycle: IUPAC rules for these systems include the parent name, prefix, sides of fusion, and numbering of the fused system
- Priority for parent heterocycles: more prior is the suffix, and the less is prefix.
- Priority is given to nitrogen-containing rings first.
- Otherwise, priority is in descending order according to the periodic table.
- The ring with the highest number of rings usually is the parent ring.
Class Activity
-
Identifying rings: Students identify heterocyclic rings in given drug structures.
-
Naming heterocyclic rings: Students need to write names for given heterocyclic rings by providing the correct prefix, the name, and suffixes.
References
- CRC Handbook of Chemistry and Physics (Robert C. Weast and Melvin A. J. 60th edition.)
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz focuses on the nomenclature of heterocyclic aromatic compounds, specifically monocyclic and fused ring systems. Students will learn to identify different heterocyclic ring structures and correctly name them using the systematic nomenclature approach. Enhance your understanding of medicinal compound naming conventions through this quiz.
