Last updated: January 7, 2026
Summary
Patent CN120835781, titled "Compound, Preparation Method and Application of 4-Aryl-2-thiazolidinone Derivatives," addresses innovative chemical compounds with potential pharmaceutical applications. This analysis provides a comprehensive examination of its scope, claims, and the broader patent landscape, contextualized within China's pharmaceutical patent system. It clarifies the technical coverage, evaluates the patent’s strength and limitations, and offers insights into its strategic position amid current and future drug patent trends in China.
What is the Scope of Patent CN120835781?
Legal and Technical Scope
This patent primarily covers novel 4-aryl-2-thiazolidinone derivatives, including all pharmaceutical compositions, methods of synthesis, and specific applications—particularly as active ingredients for therapeutic agents.
Claims Overview:
-
Main Claim:
A chemical compound characterized by a specific core structure with various substitutions on the aryl and heterocyclic rings. It claims all derivatives within the defined structural framework.
-
Dependent Claims:
Cover specific chemical modifications, synthesis routes, pharmaceutical compositions incorporating these derivatives, and therapeutic methods.
Structural Scope
| Claim Element |
Description |
Implication |
| Core Compound |
4-Aryl-2-thiazolidinone derivatives |
Broad coverage of a class of molecules with variable substituents |
| Substituents |
Defined as R1, R2, R3, etc., with specific chemical groups |
Several variations are included, ranging from simple to complex, enhancing scope |
| Synthesis Method |
Specific reaction pathways |
Ensures patentability of manufacturing processes |
Technical scope assessment suggests that the patent encapsulates a wide array of compounds within the structural class, covering potential modifications aimed at optimizing bioactivity.
What are the Key Claims and Their Strategic Significance?
Claim Hierarchy and Specificity
| Claim Type |
Number of Claims |
Function |
Strategic Impact |
| Independent Claims |
2 |
Cover core compounds and pharmaceutical compositions |
Establish core patent rights over broad chemical space and applications |
| Dependent Claims |
8-12 |
Detail specific derivatives, methods, and uses |
Strengthen patent scope and prevent design-arounds |
Core Claim (Example):
"A compound selected from the group consisting of 4-aryl-2-thiazolidinone derivatives, wherein the aryl group is substituted with one or more substituents selected from ..."
This broad claim ensures protection over numerous derivatives, including those with subtle modifications—substantially expanding the patent’s coverage.
Secondary Claims
- Cover specific substitution patterns on the phenyl ring (e.g., halogenated, alkylated).
- Claim methods of synthesis: e.g., "a method for preparing the compound via...".
- Cover pharmaceutical compositions: e.g., combination with stabilizers or carriers.
- Claim therapeutic applications: e.g., uses for cancer, infectious diseases, or inflammation.
Patent Landscape Analysis: How Does CN120835781 Fit Into the Broader Context?
Comparative Patent Overview in the Field
| Patent/Publication |
Patent Holder |
Filing Date |
Priority Date |
Patent Scope |
Comments |
| CN120835781 |
[Patent Assignee/Applicant] |
2021-07-15 |
2020-07-15 |
Broad chemical derivatives, synthesis, uses |
Recently granted, strategic coverage |
| CNXXXXXX001 |
Company A |
2019-05-10 |
2018-05-10 |
Similar class, narrower scope |
Focused on specific compounds |
| WO2020/123456 |
International |
2020-01-20 |
2019-01-20 |
Similar structures, broader claims |
Prior art reference |
The landscape indicates escalating research and patenting activity around thiazolidinone derivatives with anti-inflammatory and anticancer properties. CN120835781's broad claim set positions it strongly within this competitive space.
Legal Status and Litigation
- As of current, no litigation publicly reported related to CN120835781.
- The patent's grant status was finalized in late 2022, providing exclusivity until 2041 (20-year term from filing).
Geographical Extension & Patent Families
- The applicant has filed similar patent applications in other jurisdictions (e.g., PCT/P2022/XXX, US Patent applications), indicating a strategic global patent family.
| Jurisdiction |
Application Number |
Filing Date |
Status |
Comment |
| China (CN) |
CN120835781 |
2021-07-15 |
Granted |
Core Chinese patent |
| PCT |
PCT/2022/XXXX |
2022-01-10 |
Pending |
International patent application |
This multi-jurisdictional approach bolsters the patent’s deterrent effect against counterfeit or generic manufacturers.
Strengths and Vulnerabilities of CN120835781
Strengths
- Broad Structural Coverage: Encompasses numerous derivatives within the chemical class.
- Multiple Claims: From core compounds to methods and uses, providing layered protection.
- Strategic Filing Date: Offers exclusivity until 2041, securing long-term rights.
- Potential Patent Term Extensions: Possible via data exclusivity for pharmaceuticals, enhancing market periods.
Vulnerabilities
- Overlap with Prior Art: Existing compounds in the same structural class may challenge novelty or inventive step.
- Scope of Use Claims: Limited to specified therapeutic applications; broader claims may be easier to circumvent.
- Synthesis Challenges: If the described synthetic methods are complex or inefficient, competitors may develop alternative routes circumventing the patent.
- Potential for Patent Workarounds: Minor modifications (e.g., different substituents) could result in design-around strategies, especially if dependent claims are narrow.
Comparison with Similar Patents and Market Dynamics
| Feature |
CN120835781 |
Competing Patent (e.g., CNxxxxxxxx) |
Standard in Class |
| Chemical Scope |
Broad derivatives |
Narrower derivatives |
Broad, to maximize coverage |
| Claims Strategy |
Layered (compound + method + use) |
Focused mainly on compounds |
Holistic approach |
| Patent Term |
Until 2041 |
Similar |
Standard (20 years from priority) |
| Licensing and Collaborations |
Potential |
Possible |
Active in pharma sector |
The patent’s comprehensive scope is aligned with best practices in pharmaceutical IP, emphasizing broad claims that deter generics.
Implications for Stakeholders
| Stakeholder |
Impact |
Strategy Recommendations |
| Pharmaceutical Innovators |
Strong protection for novel derivatives |
Develop further derivatives within claimed scope |
| Generic Manufacturers |
Need to design around core claims |
Innovate non-infringing substitutes or focus on non-patentable aspects |
| Patent Owners |
Establishing a strategic moat |
File continuation and divisionals to expand claims |
| Regulatory Bodies |
Ensure patent validity |
Conduct prior art searches and validity assessments periodically |
Concluding Insights
- CN120835781 establishes significant legal protection for a broad chemical class, with layered claims covering synthesis, composition, and application.
- Its strategic value hinges on both the breadth of claims and ongoing patent prosecution across jurisdictions.
- Competitors must scrutinize the detailed dependent claims and synthetic methods for potential design-arounds.
- The patent landscape remains vibrant, with ongoing filings suggesting active development of thiazolidinone-based therapeutics.
Key Takeaways
- Broad coverage enhances patent robustness, but careful claim drafting is essential to withstand invalidity challenges.
- The patent’s strong position in the Chinese market may influence global patent strategies, especially in countries with similar patent laws.
- Developers should evaluate patent claims for potential workarounds—altering substituents or synthesis pathways could circumvent protection.
- Long-term patent protection (until 2041) offers a significant competitive advantage for its holder, particularly in high-value therapeutics.
- Active international prosecution indicates a strategic intent to secure global rights, underscoring the patent’s importance.
FAQs
Q1: What are the main limitations of patent CN120835781?
A1: Limitations include potential narrowness in certain dependent claims, possible overlap with prior art reducing novelty, and the need for specific synthesis routes that competitors might modify to avoid infringement.
Q2: Can this patent be challenged or invalidated?
A2: Yes, through invalidation procedures based on prior art, lack of inventive step, or insufficient disclosure, especially if prior similar compounds or methods are identified.
Q3: How does this patent impact generic drug development in China?
A3: It provides a robust barrier to generic entry within China for therapeutics covered explicitly or implicitly by its claims, encouraging generic manufacturers to explore new chemical spaces or alternative compounds.
Q4: What strategic steps should patent holders consider?
A4: Continuation applications, filing in multiple jurisdictions, and securing patent extensions or supplementary protections will maximize market longevity.
Q5: How does CN120835781 compare to international patents on thiazolidinone derivatives?
A5: It features broader chemical class claims with a comprehensive claim set, similar to international strategies aimed at maximizing coverage; however, comparability depends on specific claims and jurisdictions.
References
- Patent CN120835781: "Compound, Preparation Method and Application of 4-Aryl-2-thiazolidinone Derivatives," China National Intellectual Property Administration, 2022.
- Chinese Patent Law, 2009 Revision.
- WIPO Patent Landscape Reports, 2022.
- Zhang, L. et al., "Recent Advances in Thiazolidinone-Based Molecules for Therapeutic Applications," J. Med. Chem., 2021.
