What Is Thiazole?
Thiazole is a colorless to pale-yellow, transparent liquid at room temperature.
It is a heterocyclic aromatic compound with molecular formula C3H3NS and a molecular weight of 85.13. It has a characteristic unpleasant odor similar to pyridine. It is named by adding the prefix thia (thia-), meaning sulfur (S) in the ring, before azole, the name of a five-membered ring compound containing nitrogen (N). Heterocyclic aromatic compounds with S and N in the five-membered ring have two isomers: compounds with S and N adjacent (isothiazole: 1,2-thiazole) and compounds with S and N separated by one carbon (C) (thiazole: 1,3-thiazole).
It is found as a substructure of vitamin B1 (thiamine), epothilone, and other natural products. Sulfathiazole, also known as sulfa drugs (a generic term for synthetic antibacterial and chemotherapeutic agents containing a sulfonamide moiety), also contains a thiazole ring. Other thiazole azo dyes also contain a thiazole ring.
Uses of Thiazole
The main use of thiazole is as a raw material for organic synthesis.
In the thiazole ring, the 2-position reacts as a nucleophilic site and the 5-position as an electrophilic site. When a Grignard reagent or alkyl lithium is applied to thiazole, the hydrogen at the 2-position is removed and the thiazole is metalized. Also, when a nucleophile such as an amine is applied to 2-chlorothiazole, a substitution reaction occurs.
Many important derivatives of thiazole are used in industrial chemicals (vulcanization accelerators), fungicides, anthelmintics, pharmaceuticals, and dyes. Vulcanization is the bonding of rubber molecules together by sulfur to give the raw rubber high elasticity and usually requires a long time. Therefore, vulcanization accelerators are added. Thiazole-based vulcanization accelerators do not contaminate rubber and are suitable for transparent and colored products. They are also used in a variety of diene rubbers.
Regarding the use of thiazole as a disinfectant, since thiazole acts pharmacologically on microorganisms, it acts only when it is in direct contact with and absorbed by them. As a result, thiazole is used as an antiseptic in cosmetics, as a pesticide, and as a detergent in products in liquid or emulsion form.
Medicines containing the thiazole structure are mainly the antibiotic cefviron, the anticancer drug bleomycin, and thiamine (vitamin B1). It forms stable complexes with inorganic acids and mercuric chloride (II) and is therefore sold in various forms.
Other Information on Thiazole
1. Properties of Thiazole
It is a type of amine of heterocyclic aromatic compounds, but it is less basic than pyridine and other compounds. It has a melting point of -27.4°F (-33 °C), a boiling point of 244.4°F (118 °C), a flash point of 78.8°F (26 °C), a specific gravity of 1.2 g/mL (at 25 °C), a refractive index n20/D 1.538, and is liquid at room temperature. It is soluble in many organic solvents, such as ethanol and ether, and slightly soluble in water.
2. Thiazole Production Process
Thiazole is obtained by condensation of chloroacetaldehyde (ClCH2CHO) with thioformamide (HCSNH2).
It is also obtained by dehydrocyclization of N-(2-mercaptoethyl) amide with thionyl chloride and oxidation with DDQ. The thiazole ring found in natural products is thought to be formed by a similar transformation of cysteine-containing peptides in many cases.
3. Handling and Storage Precautions
Precautions for handling and storage are as follows:
- Since light and air must be avoided, fill the container with inert gas when storing.
- Keep the container tightly closed and store in a dry, well-ventilated area.
- Keep away from heat and ignition sources.
- Avoid mixing or contact with oxidizing agents or strong acids.
- Take measures against static electricity.
- Take care not to leak, overflow, or scatter, and do not unnecessarily generate vapor.
- Use ventilation and local exhaust ventilation when vapor or aerosol is generated.
- Wear protective gloves and glasses when using this product because of skin and eye irritation.
- In case of skin contact or eye contact, rinse continuously with plenty of water for several minutes