4-(1,3-BENZOTHIAZOL-2-YL)PHENOL

4-(1,3-Benzothiazol-2-yl)phenol (CAS: 6265-55-0) is a highly versatile heterocyclic phenolic building block widely employed in medicinal chemistry, materials science, and chemical biology. Featuring a conjugated architecture that couples a benzothiazole moiety with a phenol group, it offers strong π–π stacking capability, metal coordination sites (via N and S atoms), and a modifiable hydroxyl functionality, which together enable diverse intermolecular interactions and post-synthetic derivatization. Its rigid planar structure, good photophysical properties, and excellent chemical stability make it a valuable scaffold for drug discovery, fluorescent probe design, and organic electronic materials. Its primary applications are outlined below:

1. Medicinal Chemistry & Drug Discovery

Anticancer Agent Development
4-(1,3-Benzothiazol-2-yl)phenol serves as a privileged scaffold for the synthesis of kinase inhibitors and antitumor agents. Its benzothiazole core is known to interact with ATP‑binding pockets of oncogenic kinases (e.g., EGFR, VEGFR, and PI3K), while the phenolic hydroxyl group enables hydrogen bonding with key active‑site residues. Researchers utilize this scaffold in SAR studies to optimize potency, selectivity, and pharmacokinetic profiles against various cancer cell lines, including breast, lung, and colon carcinomas.

Antimicrobial & Antifungal Research
The compound and its derivatives exhibit significant activity against drug‑resistant bacterial strains (e.g., MRSA, E. coli) and fungal pathogens (Candida albicans, Aspergillus niger). The electron‑rich benzothiazole system facilitates membrane penetration and enzyme inhibition (e.g., dihydrofolate reductase, DNA gyrase). It is employed as a lead scaffold in high‑throughput screening campaigns for novel antimicrobial agents.

Anti‑inflammatory & Enzyme Inhibition
Benzothiazole‑phenol hybrids have been investigated as inhibitors of cyclooxygenase (COX), lipoxygenase (LOX), and xanthine oxidase, making them candidates for treating inflammatory disorders and gout. The phenolic group contributes to radical scavenging activity, adding an antioxidant dimension to the pharmacological profile.

Neurological Agent Design
Derivatives of this compound are explored as monoamine oxidase (MAO) inhibitors and acetylcholinesterase (AChE) inhibitors for potential applications in neurodegenerative diseases such as Alzheimer’s and Parkinson’s. The rigid aromatic framework supports favorable blood‑brain barrier penetration and target engagement.

2. Chemical Biology & Biochemical Probing

Fluorescent Chemosensors
The intrinsic photophysical properties (absorption and emission in the UV‑Vis range) of 4-(1,3-Benzothiazol-2-yl)phenol make it a valuable fluorophore for sensing applications. Researchers develop its derivatives as turn‑on or ratiometric probes for detecting metal ions (e.g., Zn²⁺, Cu²⁺, Hg²⁺), pH changes, and reactive oxygen species (ROS) in biological systems. Its phenolic OH can participate in excited‑state intramolecular proton transfer (ESIPT), enabling large Stokes shifts and enhanced sensitivity.

Enzyme Activity Assays
The compound is used as a substrate or competitive inhibitor in enzymatic assays to study cytochrome P450 isoforms, peroxidases, and sulfotransferases. Its well‑defined spectral properties allow real‑time monitoring of enzyme kinetics and inhibitor screening.

Protein–Ligand Interaction Studies
Owing to its planar aromatic surface and hydrogen‑bond donor/acceptor groups, this scaffold is employed in surface plasmon resonance (SPR) and fluorescence polarization assays to investigate protein–ligand binding. It serves as a molecular probe for mapping binding sites on transporters, receptors, and serum albumins.

3. Materials Science & Organic Electronics

Organic Light‑Emitting Diodes (OLEDs)
The rigid conjugated structure and high thermal stability of 4-(1,3-Benzothiazol-2-yl)phenol make it an attractive building block for hole‑transporting and emissive materials in OLEDs. Its derivatives are incorporated into small‑molecular emitters and host materials for blue‑to‑green electroluminescent devices.

Organic Photovoltaics (OPVs) & Semiconductors
The electron‑deficient benzothiazole moiety combined with the electron‑donating phenol group creates a donor–acceptor (D–A) architecture suitable for organic semiconductors. Researchers utilize this scaffold in the design of low‑bandgap polymers and small molecules for bulk‑heterojunction solar cells and organic field‑effect transistors (OFETs).

Fluorescent Dyes & Pigments
The compound serves as a core intermediate for the synthesis of fluorescent dyes with applications in textile coloring, biological staining, and optical brighteners. Its derivatives exhibit tunable emission wavelengths through substitution at the benzothiazole or phenol positions.

4. Coordination Chemistry & Catalysis

Metal–Organic Frameworks (MOFs) & Coordination Polymers
The phenolic OH and benzothiazole N/S atoms act as multidentate coordination sites for transition metals (e.g., Zn, Cu, Pd, Pt). This compound is used as an organic linker in the construction of MOFs and coordination polymers with applications in gas storage, heterogeneous catalysis, and luminescent sensing.

Ligand for Organometallic Catalysis
Derivatized forms serve as supporting ligands for palladium and ruthenium catalysts in cross‑coupling reactions (Suzuki, Heck, and Buchwald–Hartwig). The tunable electronic properties of the benzothiazole‑phenol system enable fine‑control over catalytic activity and selectivity.

5. Analytical Chemistry & Sensor Development

Electrochemical Sensors
The redox‑active phenolic group enables the use of this compound in electrochemical sensing platforms for detecting heavy metals, glucose, and biomarkers. Its immobilization on electrode surfaces (e.g., carbon paste, gold, or graphene) facilitates signal amplification and selective detection.

pH & Ion Probes
The pH‑dependent deprotonation of the phenolic OH results in distinct spectral shifts, making it useful as a ratiometric pH indicator in biological fluids and environmental samples. Derivatives with crown ether or chelating groups extend its utility as ion‑selective optical sensors.

6. Agrochemical Research

Pesticide & Herbicide Lead Discovery
Benzothiazole scaffolds are known to interfere with mitochondrial respiration and photosynthetic electron transport in pests and weeds. 4-(1,3-Benzothiazol-2-yl)phenol is used as a starting point for SAR optimization in the development of novel fungicides, insecticides, and herbicides with reduced environmental persistence.

Plant Growth Regulators
Certain derivatives exhibit auxin‑like or cytokinin‑modulating activity, influencing root development, flowering, and stress responses in crop plants. Researchers evaluate these compounds in greenhouse and field trials for agricultural applications.

7. Handling & Storage

Storage Conditions
Store in tightly sealed, light‑resistant containers under inert atmosphere (N₂ or Ar) at 2–8 °C, protected from moisture and strong oxidizing agents. The compound shows good stability under recommended conditions but may degrade upon prolonged exposure to light or alkaline environments. Stock solutions in DMSO or ethanol should be prepared fresh or stored at –20 °C for short‑term use.

Solubility & Preparation
Soluble in organic solvents such as dimethyl sulfoxide (DMSO), ethanol, methanol, acetone, and tetrahydrofuran (THF); poorly soluble in water. For biological assays, dissolve in DMSO and dilute with aqueous buffers (pH 7.4) to achieve desired concentrations; note that higher pH (>8) may promote deprotonation of the phenol group, affecting solubility and binding properties.

Intended Use
This product is intended for research and development purposes only. It is not for human therapeutic use, clinical diagnostics, veterinary applications, or food consumption. Standard laboratory safety practices (chemical fume hood, gloves, eye protection) should be followed during handling.

Summary

The value of 4-(1,3-Benzothiazol-2-yl)phenol lies in its unique combination of a rigid conjugated benzothiazole core, versatile coordination sites, and a modifiable phenolic hydroxyl group, which together enable its application across multiple research disciplines. Its well‑defined photophysical properties support its use as a fluorescent probe and sensor building block; its ability to engage in π–π stacking and hydrogen bonding makes it a privileged scaffold in medicinal chemistry for anticancer, antimicrobial, and anti‑inflammatory drug discovery; and its donor–acceptor character positions it as a key intermediate in materials science for OLEDs, OPVs, and coordination polymers. Reliable synthetic accessibility, established derivatization chemistry, and proven utility in enzyme inhibition studies and metal sensing make this compound a dependable standard for pharmaceutical research, chemical biology, and advanced materials development worldwide.

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