Benzothiazole, 6-ethynyl- (9CI)

Eh, this "Benzothiazole, 6-ethynyl - (9CI) " is one of the organic compounds. Its chemical structure can be analyzed from the name. "Benzothiazole" is the base of benzothiazole, which is a heterocyclic structure containing sulfur and nitrogen, fused from a benzene ring and a thiazole ring. In the structure of benzothiazole, the benzene ring is a six-membered carbon ring, which has the stability of a conjugated system; the thiazole ring is a five-membered heterocyclic ring containing sulfur and nitrogen, and the sulfur and nitrogen atoms occupy one place each in the ring.
And "6-ethynyl -" indicates that at the 6th position of the benzothiazole structure, there is an acetylene group attached. The ethynyl group is - C ≡ CH, with a triple bond structure, its electron cloud density is high, and its chemical properties are active.
Thus, the chemical structure of "Benzothiazole, 6 -ethynyl - (9CI) ", that is, benzothiazole is used as the parent nucleus, and its No. 6 position is introduced into the specific organic compound structure formed by ethynyl group. This structure endows the compound with unique physical and chemical properties, which may have special uses in the fields of organic synthesis, medicinal chemistry, etc.

6-Ethynylbenzothiazole (9CI) has the following physical properties:
This compound is mostly in solid form at room temperature. Due to the presence of various forces between molecules, it has a relatively stable aggregation state. In terms of melting point, due to the joint action of benzothiazole ring and ethynyl group in the molecular structure, the intermolecular interaction is more complicated, and its melting point is within a certain range. However, the exact value needs to be accurately determined by experiments.
In terms of solubility, the substance is insoluble in water. Water is a solvent with strong polarity, while the molecular polarity of 6-ethynylbenzothiazole is relatively weak. According to the principle of "similar miscibility", it is difficult to form an effective interaction with water molecules, so the solubility in water is very small. However, in organic solvents, such as common dichloromethane, chloroform, toluene, etc., because the benzene ring and other parts of the molecular structure have similar structural characteristics to organic solvents, they can form van der Waals forces and other interactions with them, thus showing a certain solubility.
Its density is usually larger than that of water, because the molecule contains atoms with relatively large atomic mass such as sulfur, and the molecular structure is relatively compact, so the mass per unit volume is relatively high.
From the appearance, pure 6-ethynylbenzothiazole usually exhibits a white to light yellow powder or crystal shape, and the generation of color is related to the absorption and reflection characteristics of the molecular structure. The conjugated system in the molecule absorbs light of a specific wavelength, and then visually presents the corresponding color.

The common uses of 6-ethynylbenzothiazole (9CI) are as follows:
This compound has a crucial function in the field of organic synthesis. First, it can be used as an intermediate in organic synthesis. With its alkynyl and benzothiazole structures, it has undergone various chemical reactions, such as nucleophilic substitution and cyclization addition, to build more complex and delicate organic molecular structures. Chemists can use its active reactivity of acetynyl groups to combine with various electrophilic reagents to grow carbon chains or introduce unique functional groups, laying the foundation for the creation of organic compounds with specific properties and structures.
In the field of materials science, 6-acetynylbenzothiazole also has its uses. Due to its structure endowing compounds with certain stability and unique electronic properties, it can be used as a basic raw material to participate in the preparation of materials with special properties. For example, in the preparation of optoelectronic materials, through rational design and modification, it can become a key component in the construction of materials with high charge transport properties or unique optical properties. It is used in organic Light Emitting Diodes (OLEDs), solar cells and other optoelectronic devices to improve the performance and efficiency of the device.
In the field of pharmaceutical chemistry, benzothiazole compounds often have a variety of biological activities. 6-Ethynylbenzothiazole may be used as a lead compound to develop new drugs with specific pharmacological activities by modifying and optimizing its structure. Researchers can explore the interaction patterns with specific targets in organisms, and then design and synthesize drug molecules with potential therapeutic effects for specific diseases, such as anti-tumor, antibacterial, and anti-inflammatory drugs.

The synthesis of 6-ethynylbenzothiazole (Benzothiazole, 6-ethynyl- (9CI)) has been done many times in the past. First, it starts with benzothiazole containing a specific substituent, and through halogenation, a halogen atom is introduced at the 6 position of benzothiazole. Halogenating agents such as N-bromosuccinimide are used to obtain 6-halobenzothiazole. Then, it is reacted with acetynylation reagents, such as acetynyltrimethylsilane, under the condition of palladium catalysis and the presence of a base. The palladium catalyst can be selected from palladium acetate, etc., and the base can be selected from potassium carbonate, etc., and a cross-coupling reaction occurs to form 6 - (trimethylsilylethynyl) benzothiazole. Finally, after desilication, it is treated with tetrabutylammonium fluoride and other reagents to obtain 6-ethynylbenzothiazole.
Another method is to prepare an intermediate containing an appropriate substituent and having an active check point at the 6 position of benzothiazole. Under the harsh conditions of low temperature, anhydrous and anaerobic, the active check point at the 6 position is directly alkynylated with a suitable alkynylation reagent, such as alkynyl lithium reagent or Grignard reagent. This process requires very high reaction conditions and requires fine control to obtain products with higher yield and purity.
Another way is to start from the stage of constructing benzothiazole rings. Ethynyl-containing o-aminothiophenol derivatives and suitable carbonyl compounds are cyclized and condensed under the action of acid catalysis or condensation agent. The acid can be selected as p-toluenesulfonic acid, condensation agent such as dicyclohexyl carbodiimide, and a one-step cyclization reaction to construct the ethylene-containing benzothiazole structure. However, each method has advantages and disadvantages, and the actual synthesis needs to be weighed according to the availability of raw materials, reaction conditions and the purity of the target product.

6-Ethynylbenzothiazole (9CI) is useful in various fields. In the field of pharmaceutical research and development, this compound may have unique pharmacological activity. Its structural properties may enable it to bind to specific biological targets, such as proteins, enzymes, etc. Or it can act as a lead compound, paving the way for the creation of new drugs to combat various diseases, such as cancer, inflammation and neurological diseases. The presence of its acetynyl group may endow it with good membrane permeability and biological activity.
In the field of materials science, 6-ethynylbenzothiazole may be used to construct new organic materials. Due to its stable structure and reactive check point, it can be polymerized or combined with other materials to prepare materials with special properties, such as optical materials, electrical materials, etc. It can be used in organic Light Emitting Diode (OLED) to improve its luminous efficiency and stability; or it has emerged in the field of sensor materials. With its specific reaction with specific substances, it can achieve highly sensitive detection of targets.
In the field of organic synthesis chemistry, 6-ethynyl benzothiazole is an important synthetic intermediate. Its ethynyl group can participate in many classical organic reactions, such as coupling reactions, cyclization reactions, etc. Through these reactions, chemists can synthesize compounds with more complex and diverse structures, expand the molecular library of organic compounds, and lay the foundation for subsequent research and application. In short, 6-ethynylbenzothiazole has shown considerable application potential in many fields such as medicine, materials and organic synthesis.