A Comprehensive Overview of Thiazole: Structural Features, Application Value, Selection Considerations, and Product Navigation (Tables 1–4)

I. Why Is Thiazole Worth Understanding?

In heterocyclic chemistry, five-membered aromatic rings containing heteroatoms have always occupied an important position because, within a relatively small molecular size, they can simultaneously provide molecular recognition capability, electronic tunability, and room for subsequent modification. Thiazole is a particularly representative member of this family: it is small enough to be introduced into larger molecules as a unit for scaffold replacement or fragment optimization, while also possessing clear electronic characteristics and recognizable reactivity trends that facilitate systematic structural modification and structure–activity relationship studies. For this reason, thiazole is useful not only in a single field, but as a broadly applicable scaffold spanning pharmaceuticals, agrochemicals, materials science, and flavor chemistry.

Another important reason is that thiazole is not only useful, but also readily accessible and easy to derivatize. Compared with many more complex heterocycles, thiazole has well-established classical synthetic routes. The Hantzsch thiazole synthesis frequently cited in the literature constructs the thiazole ring by condensation/cyclization of an α-haloketone or other α-halo carbonyl compound with thiourea or a thioamide. This makes thiazole suitable both as a final scaffold and as a highly practical platform for series diversification and building-block development.

II. What Is Thiazole?

Structurally, thiazole belongs to the azole family of heterocycles and is a planar, conjugated, aromatic five-membered ring. Unless otherwise specified, the term “thiazole” usually refers to 1,3-thiazole, in which sulfur and nitrogen occupy the 1- and 3-positions. It is a positional isomer of isothiazole. Although the two have similar names and the same elemental composition, the relative positions of sulfur and nitrogen in the ring are different, so their electronic distribution, reactivity, and applications should not be treated as interchangeable.

 

Thiazole is also easily confused with several closely related ring systems, including isothiazole, thiazoline, and thiazolium. Among these, thiazoline is a more hydrogenated related five-membered ring, so its aromaticity and reactivity differ from those of thiazole; thiazolium is a positively charged thiazole-related ring system that is especially important in coenzyme chemistry and organocatalysis. Keeping these concepts clearly distinguished is a prerequisite for understanding the properties and applications of thiazole.

Comparison of Commonly Related Ring Systems

Name	Core Structural Feature	Relationship to Thiazole	Key Point for Research Use
Thiazole	Five-membered aromatic ring containing one S and one N	Main subject of this article	Usually refers to 1,3-thiazole unless otherwise specified
Isothiazole	Five-membered aromatic ring, but with different relative positions of S and N	Not the same scaffold	Should not be discussed as a direct substitute for thiazole
Thiazoline	Related five-membered ring, but more hydrogenated	Related scaffold	Aromaticity and reactivity are different
Thiazolium	Positively charged thiazole-related ring system	Functionally very important	Closely related to vitamin B1 / ThDP chemistry

III. What Structural Features Does Thiazole Have?

1. A small yet stable aromatic scaffold

Thiazole is a typical aromatic heterocycle. Because of electron delocalization within the ring, it retains the relative stability of an aromatic system while not being as difficult to modify as a completely inert aromatic hydrocarbon. This balance—stable yet still readily editable—makes thiazole highly suitable as a core scaffold in synthesis and optimization.

2. Compact in size, yet able to provide clear recognition information

The thiazole ring is not large, but within this compact scaffold it can simultaneously provide an aromatic plane, a defined polarity pattern, and heteroatom sites. Thiazole contains both a pyridine-like nitrogen and a sulfur atom that participates in aromatic delocalization; as a result, it can offer relatively well-directed heteroatom recognition sites while retaining the electronic tunability of a planar aromatic scaffold.

This means that in drugs or functional molecules it can often introduce a relatively rich set of “recognition information” at a modest structural cost, which is favorable both for interactions with biological targets or the surrounding environment and for fine-tuning electronic properties, polarity distribution, and overall molecular behavior through substituent changes.

3. Site-selective reactivity follows recognizable trends

In common 1,3-thiazole systems, C5 is usually the more common site for electrophilic substitution; by contrast, in thiazoles bearing a 2-H, the C2 position is often associated with deprotonation, metalation, and subsequent functionalization design. These are best treated as empirical starting points rather than absolute rules, because the actual regioselectivity is still jointly influenced by substituents, ring fusion patterns, substrate electronics, and reaction conditions. In other words, thiazole shows clear regularity in site reactivity, but specific synthetic design still requires comprehensive judgment based on the substrate structure and the reaction system.

4. Able to serve both as a pharmacophore and as a functional unit

In medicinal chemistry, thiazole is often used as a compact heteroaryl pharmacophore; in materials chemistry—especially in fused, linked, or extended thiazole systems—it can also function as a planar, rigid, and electronically tunable structural unit. That is, the value of thiazole is not merely “adding one more heterocycle,” but rather bringing integrated structural, electronic, and functional benefits to a molecule.

IV. Understanding with a Representative Example: What Role Does Thiazole Actually Play in a Molecule?

If one representative example is needed to understand thiazole-related ring systems, vitamin B1 (thiamine) and its active coenzyme form ThDP/TPP are almost unavoidable. ThDP (TPP) is the active coenzyme form of vitamin B1, and its key chemical function arises from the positively charged thiazolium ring: this ring markedly enhances the reactivity of the C2 position and stabilizes ylide/C2-carbanion-type intermediates, thereby playing a central role in enzyme-catalyzed transketolation, decarboxylation, and C–C bond rearrangement processes. This example clearly shows that the value of a thiazole-related ring system in a molecule is not limited to providing a heterocyclic scaffold; it may directly help determine the molecule’s core chemical behavior.

V. Overview of the Main Application Areas of Thiazole

Application Area	Common Form	Typical Role Played by Thiazole
Medicinal chemistry	Thiazole-containing drugs, lead compounds, pharmacophore fragments	Provides a compact heteroaryl ring, recognition sites, and tunable electronic effects
Anti-infective drug design	2-Aminothiazole-related side chains or core fragments	Acts as a classical design element for antibacterial activity optimization
Agrochemicals	Active scaffold or intermediate fragment	Used to build biologically active molecular frameworks
Materials and sensing	MOF / COF ligands, extended conjugated units	Provides rigidity, planarity, N/S sites, and luminescence/recognition potential
Flavor chemistry	Thiazole and related derivatives	Contributes characteristic meaty, roasted, nutty, and related odor notes

1. Medicinal chemistry

Published reviews have reported that the thiazole scaffold appears in more than 18 FDA-approved drugs (this number may change depending on the scope of the survey and the approval of new drugs), covering antibacterial, anti-inflammatory, antifungal, antitumor, antigout, and anticoagulant applications, among others. A common reason underlying these applications is that thiazole can provide high structural information density within a small molecular volume, which is advantageous both for target binding and for detailed structure–activity relationship optimization.

2. Anti-infective drug design

Thiazole is especially representative in the anti-infective area. In anti-infective drug design, one of the most representative examples of 2-aminothiazole is the aminothiazolyloximino cephalosporin subgroup among third-generation cephalosporins; this side-chain design is closely related to the optimization of antibacterial spectrum and β-lactamase stability. Therefore, in antibacterial side-chain optimization, β-lactam-related structure–activity relationship studies, and classical pharmacophore migration design, 2-aminothiazole remains a unit well worth prioritizing.

3. Materials and sensing

The value of thiazole in materials science is reflected more in “extended structures.” MOFs and coordination polymers containing thiazole- or thiadiazole-based ligands have been used for luminescent sensing, and recent studies on thiazole-linked COFs have shown that this type of linkage can help produce highly stable frameworks and can be applied to areas such as trace-water detection in organic solvents.

4. Flavor chemistry

In food and flavor/fragrance research, thiazoles and related heterocycles are also typical flavor components. Studies on broth and cooked-food flavor have shown that thiazoles and thiazolines can correspond to a wide range of characteristic odor notes, including meaty/umami, roasted, nutty, rice-like, and popcorn-like notes. JECFA evaluations of thiazole as a flavoring substance have indicated that, at current intake levels, its use as a flavoring agent presents “no safety concern.” It should be noted, however, that this conclusion applies to thiazole under a specific flavor-use scenario and does not mean that the safety of all thiazole-containing derivatives can be judged on that basis.

VI. When Should Thiazole-Based Compounds Be Prioritized?

Whether thiazole should be prioritized depends on whether it can simultaneously satisfy several needs: a compact structure, tunable electronics, clear recognition capability, and ease of subsequent modification. The following quick guide approaches this question from the perspective of research tasks.

Research Need or Experimental Objective	Why Thiazole Is Worth Prioritizing	Key Points to Focus on During Selection
A small heteroaromatic ring is needed, but it must carry rich functional information	Thiazole can simultaneously provide aromaticity, heteroatom sites, and electronic tuning within a small size, making it suitable as a compact scaffold unit	Whether recognition capability and room for further modification must be retained within a limited molecular size
Lead optimization or scaffold replacement is needed in medicinal chemistry	Thiazole is a high-value heterocycle frequently used in medicinal chemistry; it can serve as a pharmacophore and also supports systematic SAR studies around accessible substitution sites	Whether activity optimization, site editability, and structural compactness all need to be balanced at the same time
A classical anti-infective drug-related fragment needs to be introduced	2-Aminothiazole is a representative structural unit in cephalosporins and other anti-infective drugs, with a mature medicinal chemistry knowledge base	Whether the project involves antibacterial side-chain optimization, β-lactam-related structural studies, or pharmacophore migration design
A planar, rigid, and conjugation-capable functional unit needs to be built	Certain fused or extended thiazole systems show favorable planarity and conjugation, making them suitable for materials, sensing, and framework chemistry	Whether the system uses a simple thiazole core or a fused/extended thiazole scaffold
A scaffold with mature synthetic access is needed for rapid library construction	Thiazole has classical and well-established entry routes and is suitable for building compound libraries with systematic substituent variation	Whether parallel synthesis, building-block development, or rapid establishment of structure series is needed
Use in sensing, coordination chemistry, or framework materials is needed	The heteroatom sites in thiazole can provide coordination ability and electronic regulation, giving it value in MOFs, COFs, and luminescent recognition systems	Whether it is more appropriate to choose a thiazole-containing ligand, a linkage-type thiazole unit, or an extended conjugated system
Research on flavor molecules or sulfur-containing heterocyclic aroma components is needed	Certain thiazoles and related derivatives are important contributors to meaty, roasted, and nutty aromas	Whether the target system is a volatile small-molecule flavor system rather than a drug-like or materials-oriented derivative

VII. What Should Be Kept in Mind When Selecting or Using Thiazole-Based Compounds?

Point to Watch	Why It Matters	Practical Recommendation
First confirm that the ring is truly thiazole rather than a similar scaffold	Thiazole, isothiazole, thiazoline, thiazolium, and thiazine have similar names, but their ring types, aromaticity, and reactivity are not the same	When building a library, purchasing compounds, or searching the literature, first verify ring size, aromaticity, and whether the ring is charged
Do not equate “contains thiazole” with “has similar properties”	Properties are determined not only by the thiazole ring itself, but also by substituents, substitution pattern, ring fusion, salt form, and the overall molecular conformation	Evaluate the complete molecular structure rather than focusing only on whether a thiazole ring is present
Understand site reactivity as a trend, not as a rigid rule	C5 as a common electrophilic substitution site and C2 as a frequent handle for further functionalization are classical trends, but not absolute rules	Specific route design should still be judged in light of the substrate, substituents, and reaction conditions
Do not overestimate the independent effect of thiazole on solubility or overall properties	Thiazole can contribute a certain degree of polarity and recognition character, but overall behavior still mainly depends on the polarity distribution of the whole molecule and the surrounding substituents	In drug design, assess salt form, side chains, and the overall structure together
In materials applications, balance performance with processability	Fused or extended thiazole systems may improve planar conjugation and packing, but they may also reduce solubility, increase aggregation, and narrow the processing window	At the design stage, consider side chains, framework flexibility, and film-forming/dispersibility requirements together
Safety must always be judged compound by compound	The exposure scenarios and risk basis differ substantially among flavoring thiazoles, drug fragments containing thiazole, agrochemical intermediates, and materials-related units	Do not extrapolate a safety conclusion drawn from one use scenario to all thiazole-based compounds

VIII. Product Selection Guide for Thiazole-Related Products: Quickly Locate Tables 1–4 by Research Task

Scenario Tag	Research Task / Experimental Need	Recommended Table	Why It Fits	Representative Products in the Table
Cell-based assays	Assessment of cell viability, proliferation, cytotoxicity, or post-treatment survival	Table 1	Table 1 concentrates functional molecules that can be used directly for assay readout or biological evaluation, including classical cell viability reagents suitable for direct use in experimental systems	Thiazolyl Blue Tetrazolium Bromide (MTT)
Bioluminescence	Reporter gene assays, luciferase systems, or in vivo / cellular bioluminescence imaging	Table 1	Table 1 includes luciferase substrates and related luminescent molecules that function as direct working reagents for luminescence assays, without requiring separate synthesis from intermediates	D-Luciferin; D-Luciferin, Sodium Salt
Fluorescent probes	Nucleic acid staining, flow analysis, amyloid aggregation monitoring, or fluorescence readout experiments	Table 1	Table 1 contains ready-to-use fluorescent probes/dyes suitable for nucleic acid binding, protein aggregation detection, and related analytical scenarios	Thiazole Orange; Thioflavin T
Metabolism / enzymology	Research on vitamin B1-related culture conditions, coenzyme-dependent enzymatic reactions, metabolic pathways, or nutritional supplementation	Table 1	Table 1 includes thiazole-related vitamins and active coenzyme forms suitable for medium supplementation, enzyme activity studies, and metabolic validation	Thiamine Hydrochloride; Thiamine Pyrophosphate
Pharmacology / reference standards	Anti-infective research, pharmacological reference use, pesticide residue analysis, method validation, or active-molecule controls	Table 1	These products in Table 1 are terminal molecules with defined biological activity or reference-standard attributes, making them more suitable for direct pharmacological or analytical studies	Thiabendazole; Nitazoxanide; Sulfathiazole
Starting from the scaffold	Starting from the simplest thiazole/benzothiazole cores for structure–property studies or initial derivatization design	Table 2	Table 2 focuses on basic parent scaffolds and simple substituted derivatives, making it suitable for route design “starting from the scaffold,” property comparison, and early lead construction	Thiazole; 4-Methylthiazole; 4,5-Dimethylthiazole; Benzothiazole; 2-Methylbenzothiazole
Sulfur-containing functional molecules	Sulfur-based coordination studies, surface/material functionalization, corrosion inhibition, rubber additives, or introduction of thiol-containing fragments	Table 2	Table 2 contains mercapto-thiazole/benzothiazole functional molecules that are more relevant to sulfur-based functional applications than to simple heterocycle core studies	2-Mercaptothiazole; 2-Mercaptobenzothiazole (MBT)
Coupling-oriented construction	Using Suzuki, Stille, Negishi, SNAr, and related reactions to rapidly attach a thiazole scaffold to a target molecule	Table 3	Table 3 focuses on halogenated thiazole/benzothiazole building blocks that are most suitable as electrophilic fragments for cross-coupling and nucleophilic substitution	2-Bromothiazole; 2-Chlorothiazole; 2,4-Dibromothiazole; 2,5-Dibromothiazole; 2-Chlorobenzothiazole
Dual-site modification	Site-selective sequential coupling, rapid expansion of substitution patterns, or establishment of SAR-oriented small-molecule libraries	Table 3	Table 3 includes highly reactive platform molecules featuring dihalides or combined “bromo + amino/ester/nitrile” functionality, facilitating stepwise modification and series expansion	2,4-Dibromothiazole; 2,5-Dibromothiazole; 5-Bromo-2-aminothiazole hydrobromide; 2-amino-5-bromothiazole series
Fine derivatization	Intermediates bearing amino, carboxylic acid, ester, aldehyde, alcohol, nitrile, and related functional groups for downstream elaboration	Table 4	Table 4 focuses on multifunctional fine building blocks suitable for amidation, ester hydrolysis, reductive amination, condensation, fragment coupling, and related operations	2-Aminothiazole; 2-Aminothiazole-4-carboxylic Acid; Ethyl 2-aminothiazole-4-carboxylate; 5-Thiazolemethanol; 4-Methylthiazole-5-carbaldehyde
Fine benzothiazole precursors	Benzothiazole amino/nitrile precursors for downstream derivatization toward drugs, probes, luminescent substrates, or functional materials	Table 4	This subset in Table 4 combines a benzothiazole scaffold with further reactive sites, making it suitable for deeper structural extension and functional molecule development	2-Cyano-6-hydroxybenzothiazole; Benzo[d]thiazole-2-carbonitrile; 2-Aminobenzothiazole; 6-Aminobenzothiazole; 6-Amino-2-benzothiazolecarbonitrile

Table 1 | Functional molecules related to thiazole/benzothiazole for biological detection and pharmacology

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Thiazole-containing vitamin / coenzyme	67-03-8	T104106	Thiamine hydrochloride	For plant cell culture	The hydrochloride salt of vitamin B1, containing a fused “pyrimidine–thiazole” motif; commonly used as a vitamin supplement in cell/plant tissue culture and also in vitamin-related metabolism studies and culture-medium formulation optimization.
Thiazole-containing vitamin / coenzyme	154-87-0	T111202	Thiamine pyrophosphate	≥98%	The active coenzyme form of thiamine (TPP); a coenzyme for key enzymes such as transketolase and α-ketoacid dehydrogenases, commonly used in enzymology, metabolism, and cofactor-dependent reaction studies.
Bioluminescent substrate	103404-75-7	D1375464	D-Luciferin, Sodium Salt	Endotoxin-free, ≥99%	A classical substrate of firefly luciferase; widely used in reporter gene assays, ATP-related luminescence systems, in vivo/cellular bioluminescence imaging, and highly sensitive signal readout.
Bioluminescent substrate	2591-17-5	D755588	D-Luciferin	BioReagent, ≥99%(HPLC), synthetic	One of the natural substrates of firefly luciferase; commonly used in luminescent reporter systems, gene-expression monitoring, cell-activity tracking, and in vivo imaging studies.
Cell viability assay dye	298-93-1	D274386	3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)	Ultra pure grade	A classical colorimetric substrate for cell viability/proliferation and cytotoxicity assays; reduced by mitochondrial dehydrogenases to form formazan and used in the MTT assay.
Nucleic acid fluorescent dye	107091-89-4	T131378	Thiazol Orange	Dye content, ~90%	A typical nucleic-acid-binding fluorescent dye; fluorescence increases markedly upon binding to DNA/RNA, making it useful for nucleic acid staining, reticulocyte/platelet analysis, flow cytometry, and electrophoresis-related detection.
Benzothiazole fluorescent probe	2390-54-7	T168914	Thioflavin T	—	A classic benzothiazole fluorescent dye; fluorescence increases upon binding to amyloid fibrils, making it widely used in amyloid protein aggregation studies, β-sheet fibril formation assays, and experiments related to neurodegenerative diseases.
Thiazole-containing bioactive molecule (pesticide / reference standard)	148-79-8	T109876	Thiabendazole	Analytical standard	A benzimidazole–thiazole bioactive molecule with fungicidal/anthelmintic activity; this product is provided as an analytical standard and is commonly used in pesticide residue analysis, method validation, and related efficacy/exposure studies.
Thiazole-containing bioactive molecule (drug)	55981-09-4	N159057	Nitazoxanide	≥98%	A thiazole-derived anti-infective drug (thiazolide); often used as an API/reference molecule in antiparasitic, anti-infective, and related mechanism-of-action studies.
Thiazole-containing bioactive molecule (drug)	72-14-0	S128351	Sulfathiazole	≥98%	A classical sulfonamide antibacterial drug containing a thiazole ring; commonly used as a pharmacological reference, in analytical testing, and in studies on older drug mechanisms.

Table 2 | Core thiazole/benzothiazole scaffolds and simple sulfur-containing derivatives

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Thiazole core / simple substituted building block	288-47-1	T122421	Thiazole	≥99%	The most basic thiazole parent scaffold; used in studies of N,S-heteroaromatic reactivity, electronic effects, and coordination properties, and also serves as a starting scaffold for the synthesis of many thiazole derivatives.
Thiazole core / simple substituted building block	693-95-8	M103108	4-Methylthiazole	≥99%	A simple alkyl-substituted thiazole core; commonly used in studies of thiazole structure–property relationships, lead scaffold construction, and subsequent site-selective functionalization.
Thiazole core / simple substituted building block	3581-91-7	D119298	4,5-Dimethylthiazole	≥98%	A dimethyl-substituted thiazole core; suitable for studying how substituents affect the electronic properties, reaction sites, and hydrophobicity of thiazole, and also useful as a precursor for further functionalization.
Thiazole mercapto functional molecule	82358-09-6	M136894	2-Mercaptothiazole	≥97%	A functional molecule containing both a thiol group and N,S heteroatoms; commonly used as an S-alkylation precursor, a coordination/chelation fragment, and an intermediate for metal-surface corrosion inhibition and functional materials research.
Benzothiazole core / simple substituted building block	95-16-9	B104854	Benzothiazole	≥96%	The basic benzothiazole parent scaffold; a common fused N,S-heteroaromatic starting framework in drug discovery, fluorescent probes, functional materials, and coordination chemistry.
Benzothiazole core / simple substituted building block	120-75-2	M101883	2-Methylbenzothiazole	≥98%	A benzothiazole building block bearing an active 2-methyl group; commonly used in condensation reactions, quaternization, and the further preparation of benzothiazole dyes, probes, and medicinal chemistry derivatives.
Benzothiazole functional molecule / industrial intermediate	149-30-4	M1217837	2-Mercaptobenzothiazole(MBT)	≥98%, white powder	A classic sulfur-containing benzothiazole functional molecule; widely used in rubber vulcanization accelerator systems and also employed as an N,S-coordinating fragment and organosulfur intermediate in materials and industrial chemistry research.

Table 3 | Halogenated thiazole/benzothiazole and coupling-ready building blocks

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Halogenated thiazole building block	3034-53-5	B123649	2-Bromothiazole	≥99%	A thiazole building block activated by halogen substitution at C2; commonly used in Suzuki, Stille, Negishi, and related couplings, or as a precursor for further functional-group interconversion to rapidly construct 2-substituted thiazole scaffolds.
Halogenated thiazole building block	3034-52-4	C121869	2-Chlorothiazole	≥98%	An electrophilic C2-chloro thiazole building block; commonly used in SNAr or metal-catalyzed coupling to rapidly introduce amino, aryl, and heteroaryl fragments.
Halogenated thiazole building block	4175-77-3	D122731	2,4-Dibromothiazole	≥98%	A dihalogenated thiazole platform molecule; suitable for site-selective coupling/sequential coupling to construct 2,4-disubstituted thiazoles, heteroaryl-linked structures, and SAR libraries.
Halogenated thiazole building block	4175-78-4	D135835	2,5-Dibromothiazole	≥97%(GC)	A 2,5-dihalogenated platform; suitable for sequential coupling and regioselective modification to rapidly prepare 2,5-disubstituted thiazoles and heteroaryl-linked scaffolds.
Halogenated benzothiazole building block	615-20-3	C135221	2-Chlorobenzothiazole	≥98%(GC)	An electronically activated benzothiazole building block bearing C–Cl at C2; commonly used in SNAr to introduce amino, thiol, or alkoxy groups and rapidly prepare 2-substituted benzothiazole derivatives.
Halogenated 2-aminothiazole building block	61296-22-8	B101200	5-Bromo-thiazol-2-ylamine	≥97%	The bromo group at C5 can be used for coupling, while the amino group at C2 can undergo further acylation, urea formation, or condensation; an important precursor for constructing 5-substituted 2-aminothiazole series.
Halogenated 2-aminothiazole carboxylate building block	850429-60-6	A121876	2-Amino-5-bromo-4-thiazolecarboxylic acid methyl ester	≥97%	A high-value medicinal chemistry intermediate combining three modifiable sites—5-bromo, 2-amino, and 4-methyl ester—making it suitable for tandem design involving coupling, acylation, and ester transformation.
Halogenated 2-aminothiazole carboxylate building block	61830-21-5	E185588	Ethyl 2-amino-5-bromothiazole-4-carboxylate	≥97%	A similarly multifunctional building block; the ethyl ester is more convenient for subsequent hydrolysis/coupling and is commonly used to build polysubstituted thiazoles featuring C5 arylation and C2 amidation.
Halogenated 2-aminothiazole nitrile building block	944804-79-9	A734236	2-Amino-5-bromothiazole-4-carbonitrile	≥95%	A multifunctional 2-aminothiazole intermediate containing both bromo and nitrile groups; suitable for coupling, nucleophilic transformation, and introduction of polar fragments, and often used in complex lead optimization.

Table 4 | Multifunctional fine building blocks bearing amino, carboxylic acid (esters), nitrile, aldehyde, alcohol, and related groups

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
2-Aminothiazole building block	96-50-4	A104872	2-Aminothiazole	≥97%	One of the most classical 2-aminothiazole parent scaffolds; commonly used in medicinal chemistry lead design, acylation/urea formation/cyclization reactions, and active-fragment screening.
2-Aminothiazole building block	1603-91-4	A167666	2-Amino-4-methylthiazole	≥98%	A typical 2-aminothiazole fragment; can be used in acylation, urea formation, condensation, and further heterocycle construction, making it a common intermediate in medicinal chemistry and functional molecule design.
2-Aminothiazole carboxylate building block	5398-36-7	E119303	Ethyl 2-aminothiazole-4-carboxylate	≥98%	A classical 2-aminothiazole-4-carboxylate intermediate; commonly used to build medicinal chemistry derivatives through amidation, urea formation, transesterification, or hydrolysis followed by further coupling.
2-Aminothiazole carboxylate building block	63257-03-4	M185692	Methyl 2-amino-5-methylthiazole-4-carboxylate	≥98%	A multifunctional thiazole intermediate bearing both amino and ester groups; suitable for amidation, ester hydrolysis, and optimization of C5-substituted scaffolds, and commonly used in lead refinement.
2-Aminothiazole carboxylic acid building block	40283-41-8	A184340	2-Aminothiazole-4-carboxylic acid	≥98%	Contains two reactive sites—an amino group and a carboxylic acid—and is commonly used for amide coupling, fragment assembly, and construction of more polar thiazole-containing medicinal chemistry scaffolds.
Thiazole alcohol building block	38585-74-9	T119309	5-Thiazolemethanol	≥98%	A thiazole intermediate bearing a primary alcohol functionality; commonly used for esterification, etherification, oxidation to the aldehyde, or installation of linker arms, and is quite practical in medicinal chemistry and probe molecules.
Thiazole aldehyde building block	82294-70-0	M137054	4-methylthiazole-5-carbaldehyde	≥97%	A typical aldehyde-containing thiazole intermediate; suitable for reductive amination, Schiff base condensation, Wittig/Knovenagel reactions, and related transformations for rapid thiazole side-chain extension.
Thiazole carboxylic acid building block	3973-08-8	T119302	4-Thiazolecarboxylic acid	≥97%	A thiazole carboxylic acid coupling platform; commonly used for amide bond construction, polarity tuning, and introduction of N,S-heteroaromatic fragments.
Thiazole carboxylic acid building block	14190-59-1	T131973	Thiazole-2-carboxylic acid	≥95%	A C2-carboxylated thiazole platform; commonly used in amide coupling, heterocycle fragment assembly, and construction of more polar thiazole derivatives.
Aminobenzothiazole building block	136-95-8	A110691	2-Aminobenzothiazole	≥97%	A commonly used fragment in benzothiazole-based medicinal chemistry and probe chemistry; the amino group at C2 facilitates the introduction of amide, urea, imine, and related motifs, making it suitable for building fused N,S-heteroaromatic molecules.
Aminobenzothiazole building block	533-30-2	A113931	6-Aminobenzothiazole	≥98%	A benzothiazole scaffold bearing an amino group at C6; convenient for acylation, sulfonylation, urea formation, and dye/probe derivatization, and therefore common in medicinal chemistry and functional materials research.
Benzothiazole nitrile / luminescent precursor building block	939-69-5	H305007	6-Hydroxybenzo[d]thiazole-2-carbonitrile	≥98%	A key benzothiazole nitrile intermediate in luminescent substrate precursors; a classical key intermediate for the synthesis of D-luciferin and also useful in the derivatization of luminescent probes/substrates.
Benzothiazole nitrile building block	2602-85-9	B698545	Benzo[d]thiazole-2-carbonitrile	≥97%	A benzothiazole intermediate activated by a nitrile group at C2; suitable for subsequent hydrolysis, addition, cyclization, or further derivatization, and commonly encountered in medicinal chemistry and probe synthesis.
Aminobenzothiazole nitrile building block	7724-12-1	A186547	6-Amino-2-benzothiazolecarbonitrile	≥95%	Combines an amino group at C6 with a nitrile group at C2, allowing dual-site derivatization; commonly used to construct benzothiazole-based medicinal chemistry scaffolds, fluorescent molecules, and functional material precursors.

Note: The products listed above are representative Aladdin products. For additional specifications, please refer to the product list at the end of the article or search the Aladdin website using the product name/CAS/catalog number.

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