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Clinical courses


Clinical research courses

Chaitanya Prasad Meher
Assistant professor,
Department of pharmaceutical chemistry,
Vijaya Institute Of Pharmaceutical Sciences For Women,
Enikepadu, Vijayawada (A.P)

The chemistry of heterocyclic compounds is a vast subject. Heterocyclic chemistry is an underpinning science for a whole host of areas that are vital for mankind’s future. One of the leading heterocyclic compound is the thiazole. Thiazole and their derivatives are found in certain natural products, viz.vitamin B1 (thiamine) and penicillins. Sulphathiazole (a member of sulpha drugs) is also a derivative of thiazole. The important physiological properties of these compound have stimulated interested in thiazole chemistry.


A heterocyclic compound is an organic compound in which one or more of the carbon atoms in the backbone of the molecule has been replaced by an atom other than carbon. Typical hetero atoms include nitrogen, oxygen, and sulfur. Heterocyclic compounds play very important role in life processes. Both synthetic and natural heterocyclic compounds are the subject of R&D units of many pharmacological and agrochemical and industrial laboratories. Approximately 90% of new drugs contain heterocyclic moieties.  Synthetic heterocycles have wide spread therapeutic uses such as antibacterial, antifungal, antimicrobial, trypanocidal, anti HIV activity, genotoxic, antitubercular, antimalarial, herbicidal, analgesic, anti-inflammatory, muscle relaxant, anticancer agents, hypnotics, sedatives, antidepressant, antimalarial, anthelmentic, antiulcer, insecticidal..etc.,(actually the uses are many and difficult to record.)  With such a great importance, research in heterocyclic chemistry is part of many academic and industrial laboratories worldwide. Out of all the heterocyclic compound thiazole is one of the important area of research because of the manifold pharmacological activities.

Thiazole, or 1,3-thiazole, is a heterocyclic compound that contains both sulfur and nitrogen; the term 'thiazole' also refers to a large family of derivatives. Thiazole itself is a pale yellow liquid with a pyridine-like odor and the molecular formula C3H3NS. The thiazole ring is notable as a component of the vitamin thiamine(B1).

Thiazole is aromatic on the basis of delocalization of a lone pair of electrons from the sulfur atom completing the needed 6 π electrons to satisfy Huckel’s rule. The resonance forms are:

Thiazole is a clear to pale yellow liquid with a boiling point of 116-118oC. Its specific gravity is 1.2 and it is sparingly soluble in water. It is soluble in alcohol and ether. The odor of thiazole is similar to pyridine. It is used as an intermediate to manufacture synthetic drugs, fungicides, and dyes.Its ring structure is also a useful element in medicinal chemistry. This structure has found application in drug development for treatment of allergies, hypertension, inflammation, schizophrenia, and bacterial and HIV infections. Microwave spectra reveal the bond lengths and bond angles in the thiazole molecule. Notice that the C-S bonds are longer than the others because of the larger sulfur atom radius. The bond angles are also influenced by the presence of heteroatoms. The C-S-C angle is comparable to that of thiophene (~ 90o).

1H NMR spectral data shows the following chemical shifts: H-2 8.88 ppm, H-4 7.98 ppm, and H-5 7.41 ppm. The downfield values are typical of aromatic hydrogens. The further downfield shift for H-2 compared to the other hydrogens is due to the deshielding caused by the combined electron-withdrawing effects of nitrogen and sulfur being adjacent to it. 13C NMR spectral data reveals three peaks: C-2 153.4 ppm, C-4 143.7 ppm, and C-5 119.7 ppm, all values typical for aromatic carbons.Important IR bands include a typical C-H stretching mode at 3084 cm-1,ring stretching modes at 1481 cm-1, 1381 cm-1, and 1319 cm-1, and CH modes at 882 cm-1, 865 cm-1, 803 cm-1, and 728 cm-1.

Pharmacological uses of important thiazole derivatives

The heterocyclic compounds are used as chemical intermediates and solvents in the pharmaceutical, chemical, textile, dye-stuffs, petroleum and photography industries. Several compounds also function as vulcanization accelerators in the rubber industry.Compounds classified as heterocyclic probably constitute the largest and most varied family of organic compounds. After all, every carbocyclic compound, regardless of structure and functionality, may in principle be converted into a collection of heterocyclic analogs by replacing one or more of the ring carbon atoms with a different element. Even if we restrict our consideration to oxygen, nitrogen and sulfur (the most common heterocyclic elements), the permutations and combinations of such a replacement are numerous. These include new therapeutic agents, improved molecules to help sustain and enhance food production as well as dyes and electronic molecules that will play an important role in the conservation of energy as well as the next generation of consumer electronics.

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