5-Chloro-1,2,4-thiadiazole
[CAS# 38362-15-1]

Identification

• Classification: Organic raw materials >> Heterocyclic compound
• Name: 5-Chloro-1,2,4-thiadiazole
• Molecular Formula: C₂HClN₂S
• Molecular Weight: 120.56
• CAS Registry Number: 38362-15-1
• EC Number: 852-029-0
• SMILES: C1=NSC(=N1)Cl

Properties

• Solubility: Slightly soluble (7.5 g/L) (25 °C), Calc.^*
• Density: 1.559±0.06 g/cm³ (20 °C 760 Torr), Calc.^*
• Melting point: -8-7 °C^**
• Boiling point: 122.0-122.5 °C (758 Torr)^**
• Refractive index: 1.5388 (589.3 nm 21 °C)^**
• Flash point: 70.0±22.6 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software V11.02 (©1994-2013 ACD/Labs)

^** Goerdeler, Joachim

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H227-H302-H315-H319-H350
• Safety Statements: P210-P261-P264-P264+P265-P270-P271-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P319-P321-P330-P332+P317-P337+P317-P362+P364-P370+P378-P403-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	4	H227
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2A	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H302

Discovery and Applications

5-Chloro-1,2,4-thiadiazole (abbreviated as 5-CTD) is a compound with a unique molecular structure and wide applications, which is of great significance in various fields. The compound was first synthesized and characterized in the middle of the 20th century, and its discovery marked a milestone in the development of heterocyclic chemistry.

5-Chloro-1,2,4-thiadiazole was first synthesized by the reaction of thiourea with phosphorus oxychloride. This method allowed chemists to obtain a five-membered heterocyclic compound containing nitrogen and sulfur atoms, which had unique chemical properties compared to other heterocyclic compounds at that time.

The molecular structure of 5-CTD consists of a planar ring system with a chlorine substituent at the 5-position, which gives it specific chemical reactivity and stability characteristics. Its chemical properties include moderate acidity due to the presence of the thiadiazole ring, which can participate in various types of reactions, including nucleophilic substitution and coordination chemistry.

In agriculture, 5-chloro-1,2,4-thiadiazole derivatives are used as potential agrochemicals due to their ability to inhibit certain enzymes that are essential for the survival of pests. These derivatives are intensively studied for their herbicidal and fungicidal properties, which can help in the development of environmentally friendly crop protection agents.

In the pharmaceutical industry, 5-CTD is a valuable scaffold for the synthesis of bioactive compounds. It has potential as an antiviral and anticancer agent in drug development programs. Researchers have explored the ability of its derivatives to interact with biological targets implicated in disease processes and have demonstrated promising pharmacological activities in preclinical studies.

In addition to biological applications, 5-chloro-1,2,4-thiadiazole also has practical value in materials science, especially in the synthesis of advanced materials and coordination polymers. Its ability to coordinate with metal ions has been used to create functional materials with tunable properties, such as luminescent sensors and catalytic materials for organic transformations.

Research on 5-chloro-1,2,4-thiadiazole continues to grow, driven by its wide range of applications and potential in various scientific disciplines. Future studies aim to further explore its biological activity, improve the synthesis of derivatives, and expand its usefulness in materials science and catalysis.

References

1999. Five-Membered Heterocycles with More than Two Heteroatoms. Heterocyclic Chemistry.
DOI: 10.1007/978-3-662-07757-3_5