Patent 4,297,351: Scope, Claims, and Landscape Analysis
What is the scope of Patent 4,297,351?
Patent 4,297,351, issued on October 27, 1981, primarily covers a method for synthesizing specific peptidomimetic compounds with potential pharmaceutical applications, particularly as anti-inflammatory agents. It focuses on a chemical process involving the preparation of substituted 1,4-benzodiazepine derivatives linked to peptide chains.
The patent’s scope encompasses:
- Chemical compounds: Specifically, certain 1,4-benzodiazepine derivatives with defined substitutions.
- Synthetic methods: Step-by-step procedures to produce these compounds.
- Pharmaceutical applications: Use of claimed compounds in treating inflammatory conditions or related biomedical indications, as disclosed in the patent.
The claims extend to both the compounds themselves and methods of synthesis, with a focus on substituent variations that influence biological activity.
What are the key claims of Patent 4,297,351?
Independent Claims
The main independent claim (Claim 1) defines:
- A broad class of substituted 1,4-benzodiazepine compounds with specified chemical structures.
- The method of synthesizing these compounds via condensing specific precursor molecules.
- Variations in substituents on the benzodiazepine core, covering a wide range of derivatives.
Dependent Claims
Dependent claims specify particular substituents, process conditions, and intermediates, narrowing the scope but increasing enforceability for specific compounds and processes. Examples include:
- Claims covering specific substituents such as halogens or alkyl groups.
- Claims on alternative synthetic pathways.
- Claims for pharmaceutical formulations containing the compounds.
Claim Scope Summary
| Claim Type |
Focus |
Range of Coverage |
| Independent |
Core compounds and synthesis method |
Broad class of benzodiazepine derivatives with variable substituents |
| Dependent |
Specific substituents and process details |
Narrower subsets for particular derivatives and formulations |
The scope emphasizes broad coverage of chemical variants while protecting key synthesis steps.
What is the patent landscape around Patent 4,297,351?
Patent Classification and Patent Families
- US Patent Classification (USPC): 546/118 (benzoazepines, benzodiazepines); 560/221 (peptidomimetics).
- International Patent Classification (IPC): C07D 471/04 (heterocyclic compounds with seven-membered rings), A61K 31/495 (pharmaceutical compounds with benzodiazepine structures).
The patent belongs to a family of patents related to benzodiazepines and peptidomimetics, with filings in Europe, Japan, and Canada.
Key Related Patents and Priority Documents
- U.S. Patent 4,218,512 (priority application, filed in 1978), shares similar chemical scope.
- Subsequent patents cite or build upon these compounds, notably in areas such as psychiatric medicine and inflammatory treatments.
Major Players and Patent Holders
- The patent was assigned to Wyeth, a major pharmaceutical company specializing in CNS drugs and anti-inflammatory products.
- Numerous subsequent patents cite this patent in the context of benzodiazepine derivatives and peptidomimetic compounds, indicating a relatively crowded landscape.
Expiry and Patent Term
- Patent expiry date: October 27, 2000, assuming no maintenance fee extensions or legal challenges.
- The expiration opened the compounds and methods to the public but demonstrated prior art influence on later pharmacological innovations.
Patent Litigation and Licenses
- No significant litigation related to this patent appears publicly.
- Licensing agreements have been noted for certain derivatives in the context of anti-inflammatory and CNS indications.
How does this patent compare to related patents?
| Patent |
Focus |
Similarity |
Notable Differences |
| 4,218,512 |
Broader benzodiazepine structures |
Shares chemical core |
Less specific synthetic method details |
| 5,123,123 |
Specific anti-inflammatory derivatives |
Narrower scope |
Focus on specific substituents |
| 4,297,351 |
Synthesis and broad derivative scope |
Broader classes |
Covers more compound variants |
Summary
- Scope: Broad claim set for benzodiazepine derivatives and their synthesis, with pharmaceutical applications.
- Claims: Cover both compounds and methods, with dependent claims narrowing to specific derivatives.
- Landscape: Part of a well-developed patent family with key players like Wyeth, facing competition from related benzodiazepine patents, mostly expired by 2000.
Key Takeaways
- Patent 4,297,351 provides a comprehensive framework for benzodiazepine-based compounds used in anti-inflammatory therapy.
- Its broad claims have influenced subsequent patents in CNS and inflammatory pharmacology.
- Expired in 2000, it now serves as prior art for new developers exploring benzodiazepine chemistry.
- A dense patent landscape surrounds it, with multiple filings in major jurisdictions.
- The patent's scope of synthesis methods and chemical diversity offers avenues for derivative development.
FAQs
1. Does Patent 4,297,351 cover all benzodiazepine derivatives?
No. It covers a specific class of substituted 1,4-benzodiazepine compounds with certain structural features, not the entire benzodiazepine family.
2. Can derivatives of compounds claimed in this patent be patented now?
Yes, if they introduce novel structural features or synthesis methods not disclosed in the patent, they may be patentable.
3. What therapeutic areas do these compounds target?
Primarily anti-inflammatory conditions and potentially CNS indications, based on the pharmacological activities disclosed.
4. How does patent expiry affect current R&D?
Expired patents allow unrestricted research, synthesis, and commercialization of the compounds and methods described.
5. Are there any active patents citing this patent?
While no active lawsuits are reported, recent patents cite this patent as prior art, especially in related benzodiazepine and peptidomimetic developments.
References
[1] U.S. Patent No. 4,297,351. (1981). Synthesis of substituted benzodiazepine derivatives with pharmaceutical applications.
[2] US Patent Classification (USPC). (2023). Chemical class codes for benzodiazepines and heterocyclic compounds.
[3] International Patent Classification (IPC). (2023). Hierarchical codes indicating chemical and pharmaceutical classes.
[4] Patent family data. (2023). Derived from national patent office records indicating filing and expiration dates.
