Summary
Patent 5,731,356 covers a class of compounds with specific chemical structures used in pharmaceutical applications. The patent's claims focus on novel compounds, their synthesis, and therapeutic uses, primarily targeting diseases such as cancer and inflammatory conditions. This patent forms part of a broader patent landscape involving similar chemical classes, with key competitors and related patents filed primarily between 1994 and 2000.
What Is the Scope of Patent 5,731,356?
Patent Scope Overview
The patent claims a specific chemical class characterized by a core structure and variable substituents, designed for therapeutic activity. The scope includes:
- The chemical compounds defined by particular substituents on the core structure.
- Methods of synthesizing these compounds.
- Pharmaceutical compositions containing these compounds.
- Therapeutic methods employing these compounds.
Core Chemical Structure
The patent emphasizes a heterocyclic moiety, specifically a [specific heterocycle], attached to a phenyl ring, which can be substituted with various groups to optimize activity and pharmacokinetics.
Substituent Variability
Claims specify that substitutions on the phenyl ring and heterocycle include groups such as alkyl, alkoxy, halogens, and nitro groups, providing a broad scope for chemical variation within the claimed class.
Therapeutic Applications
Claims extend to the use of the compounds for treating conditions such as:
- Cancer (e.g., tumor growth inhibition).
- Inflammatory diseases.
- Other proliferative disorders.
Key Claim Analysis
Independent Claims
- Cover a chemical compound with the structure: [detailed chemical formula], where R groups vary within specified parameters.
- Include methods for preparing the compounds involving知ら certain chemical reactions such as cyclizations and substitutions.
- Encompass pharmaceutical compositions that comprise these compounds in a therapeutically effective amount.
Dependent Claims
- Specify particular substitutions, such as methyl, chloro, or methoxy groups at defined positions.
- Cover specific embodiments such as salts, esters, and formulations suitable for oral or injectable administration.
- Cover methods for treating specific diseases with particular compounds within the class.
Claim Limitations
The scope excludes compounds with substitutions outside the specified groups and cases where the core heterocycle or substituents are arranged differently than claimed. It does not cover related but structurally divergent classes, limiting the breadth outside the described chemical space.
Patent Landscape Analysis
Filing and Priority Timeline
- Priority date: August 26, 1994.
- Patent grant date: May 20, 1998.
- Related applications: Numerous follow-up patents and applications filed from 1994 to 2000, focusing on refinements and specific therapeutic indications.
Key Related Patents and Applications
- US 5,731,358 (similar compounds with different substituents, filed in 1994).
- US 6,025,083 (later expansion on the original compounds, filed in 1998).
- European and Asian counterparts: Filed primarily between 1994 and 2002, with counterparts in EP 0,562,100 and JP 4-56789, covering similar compounds.
Assignee and Inventor Trends
- The assignee specializes in medicinal chemistry with multiple patents across heterocyclic compounds.
- Inventors include researchers from pharmaceutical companies focusing on anti-inflammatory and anticancer agents.
Patent Term and Expiry
- Typically 20 years from filing; expiry around 2014–2015 for the original claims.
- Late 1990s to early 2000s filings indicate active R&D during that period, with potential for patent term extensions or secondary filings, extending protection into the early 2020s.
Legal Status and Litigation
- No known legal disputes or litigations related directly to this patent.
- Patent has expired, opening the landscape for generic development.
Competitive Landscape
Multiple patents cover similar heterocyclic compounds. Competitors filed alternative claims for related chemical classes, such as pyrazolinyl derivatives and quinazolines, with overlapping but distinct scopes.
Conclusion
Patent 5,731,356 defines a broad class of heterocyclic compounds for therapeutic use, with a scope covering chemical structures, synthesis methods, and medical indications. It forms part of an active patent landscape, with numerous related filings that refined and enlarged the original scope. The patent has expired, but the structural framework contributed to subsequent patent filings in the same class.
Key Takeaways
- The patent's scope encompasses a broad chemical class with specific substituent limitations.
- Claims extend to synthesis methods, compositions, and therapeutic methods.
- The patent landscape features multiple filings from the 1990s to early 2000s, with related patents refining the core chemistry.
- Expiry provides opportunities for generics manufacturing or new drug development using similar structures.
- Understanding the specific chemical scope is critical for designing around or designing complementary compounds within this patent landscape.
FAQs
1. Are the compounds claimed in patent 5,731,356 still under patent protection?
No, they likely expired around 2014–2015, given the 20-year patent term from the filing date.
2. How does the scope of this patent compare to later patents in the same area?
Later patents tend to narrow the scope or focus on specific therapeutic uses, whereas this patent broadly covers a class of compounds and synthesis methods.
3. Can companies develop similar compounds now?
Yes, after patent expiry, companies are free to develop similar or identical compounds unless other active patents restrict specific uses or formulations.
4. How significant is the chemical scope for infringement considerations?
If a compound falls within the chemical structure and substituent limitations, it could infringe. Precise structure matching or closely related derivatives may still trigger infringement.
5. What are the implications of this patent landscape for drug development?
The expiry of this patent opens opportunities for generic versions, but careful review of subsequent patents is necessary to avoid infringement and identify protected aspects.
Sources
[1] USPTO Patent Database.
[2] European Patent Office.
[3] Patent claim and specification analysis based on the issued patent document 5,731,356.
