Course Objectives :
The course aims to provide a broad introduction to heterocyclic chemistry and its nomenclature. Emphasis is given on some important heterocyclic systems, such as aziridines, oxiranes, oxetanes, benzopyrroles, benzofurans, benzothiophenes, pyrones, diazines, triazines, thiazines, and meso-ionic heterocycles. For each group, students will be acquainted with ring synthesis, chemical properties and characteristic reactions.
Course Outcomes (Cos):
COURSE |
Learning outcomes (at course level) |
Learning and teaching strategies |
Assessment Strategies |
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Paper Code |
Paper Title |
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CHY 423(B) |
Heterocyclic Chemistry |
The students will be able to-
CO142-learn and understand the specific properties and biological activities of some important heterocycles. CO143-describe mechanisms for reactions involving heterocycles as starting materials, intermediates and products, and be able to propose syntheses of heterocycles from the major classes and assign their names. |
Interactive Lectures
Discussions
Tutorials
Quiz
Problem solving |
PowerPoint Presentation
Written test
Google Quiz
Assignment
Semester End Exam |
Replacement and systematic nomenclature (Hantzsch-Widman system) for monocyclic, fused and bridged heterocycles.
General chemical behaviour of aromatic heterocycles, classification (structural type), criteria of aromaticity (bond lengths, ring current and chemical shifts in 1H NMR-spectra, empirical resonance energy, delocalization energy and Dewar resonance energy, diamagnetic susceptibility exaltations), heteroaromatic reactivity and tautomerism in aromatic heterocycles.
Strain-bond angle, torsional strains and their consequences in small ring heterocycles. Conformation of six-membered heterocycles with reference to molecular geometry, barrier to ring inversion, pyramidal inversion and 1,3-diaxial interaction, stereo-electronic effects: Anomeric and related effects, attractive interactions: Hydrogen bonding and intermolecular nucleophilic-electrophilic interactions.
Three-membered and four membered heterocycles: Synthesis and reactions of aziridines, oxiranes, thiiranes, azetidines, oxetanes and thietanes, five membered heterocycles: synthesis and reactions of different isomers of diazoles (pyrazoles, imidazoles), oxazoles, thiazoles, 1,2,4-triazole, oxadiazole, thiadiazole, 1,2,3,4-tetrazole.Porphyrins and applications.
Synthesis and reactions including medicinal applications of benzopyrroles, benzofurans and benzothiophenes. Meso-ionic heterocycles: Classification, chemistry of some important meso-ionic heterocycles of type-A and B and their applications. Sydnones.
With one heteroatom: Synthesis and reactions of pyrilium salts and pyrones and their comparison with pyridinium and thiopyrylium salts and pyridones; synthesis and reactions of quinolizinium and benzopyrylium salts, coumarins and chromones.
With two or more heteroatoms: Synthesis and reactions of diazines, triazines, tetrazines and thiazines.Some important macroheterocycles.