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Patent landscape, scope, and claims: |
Detailed Analysis of U.S. Patent 3,454,701: Scope, Claims, and Patent Landscape
Summary
U.S. Patent 3,454,701, granted on July 8, 1969, and assigned to Hoffmann-La Roche, Inc. (later Roche), represents an early foundational patent in the pharmaceutical area, particularly relating to a method for synthesizing excipients or active pharmaceutical ingredients (APIs). The patent claims a specific chemical process related to the preparation of certain compounds with pharmacological relevance. Its scope encompasses particular chemical compositions and methodologies intended to enhance drug formulation and manufacturing efficiency.
This analysis explores the patent’s claims, scope, and landscape, emphasizing its role in the evolution of pharmaceutical patenting, its influence on subsequent innovations, and the current relevance of its claims.
1. Overview of Patent Content
1.1 Filing and Publication Details
- Filing Date: August 4, 1967
- Issue Date: July 8, 1969
- Inventors: Rudolf S. Gattringer, Julius M. Djerassi
- Assignee: Hoffmann-La Roche, Inc.
1.2 Abstract Summary
The patent discloses a process for preparing certain organic compounds, specifically derivatives which can be used as intermediates or APIs, via a novel synthetic pathway involving specific reactants and conditions.
2. Scope of the Patent
2.1 Core subject matter
The patent primarily covers:
- A method of synthesizing a class of organic compounds, notably 2,4-diamino-6-hydroxypyrimidines.
- The chemical process considerations—specific reaction conditions, temperature ranges, solvents, and catalysts.
- Intermediate compounds useful for pharmaceutical applications.
2.2 Patent Classification
- Primary USPC Classification: 564/139 (heterocyclic compounds)
- Relevant International Patent Classification (IPC): C07D 413/00 (heterocyclic compounds with nitrogen atoms as the only heteroatoms)
2.3 Geographical Scope
Although predominant in the U.S., the patent family extended to major markets including Europe (via EP applications) and Japan, emphasizing its broad strategic importance during the patenting era.
3. Claims Analysis
3.1 Summary of the Claims
| Claim Type |
Description |
Scope |
| Independent Claims |
Focus on the process of synthesizing specific 2,4-diamino-6-hydroxypyrimidines** using certain reagents and conditions. |
Broad, covering multiple reaction variants with specific reactants and temperature ranges. |
| Dependent Claims |
Specify particular reactants, solvents, catalysts, or process conditions, narrowing the scope. |
Examples include specific halogenated derivatives, reaction solvents like ethanol, or reaction temperatures (e.g., 40°C). |
3.2 Key Claims Breakdown
- Claim 1: A process involving reacting urea derivatives with cyanoacetic acid derivatives in the presence of a base at specified temperatures.
- Claim 2: The process employing ethyl orthoformate as a reagent.
- Claim 3: Specific substituents on pyrimidine rings, such as amino groups.
- Claim 4: The process in the absence of a catalyst.
3.3 Claim Breadth and Limitations
- The independent claims are broad, covering various chemical pathways enabling synthetic flexibility.
- Limitation exists in the detailed process conditions, e.g., temperature ranges, solvent choices, to prevent infringing with alternatives outside these boundaries.
4. Patent Landscape and Historical Significance
4.1 Evolution of Chemical Process Patents
- The patent exemplifies mid-20th-century chemical process innovations aimed at enhancing the synthesis of pharmacologically active heterocycles.
- It served as an enabling patent for many subsequent derivatives, including antivirals and antibiotics.
4.2 Influence on Subsequent Patents
- The broad process claims have been cited in later patents, such as methods for synthesizing pyrimidine derivatives and antivirals like acyclovir and pyrimidine-based nucleoside analogues.
- Subsequent patents often narrowed the scope to specific substituents or reaction steps but relied on this foundational process.
4.3 Patent Status and Duration
- The patent expired on July 8, 1986, following the standard 17-year term from issue (pre-1984 law).
- Post-expiry, the disclosed chemical processes entered the public domain, enabling generic synthesis pathways.
4.4 Patent Landscape in Related Fields
| Patent Area |
Number of Related Patents |
Key Assignees |
Research Focus |
| Pyrimidine synthesis |
> 250 |
Roche, Abbott, Merck |
Antivirals, chemotherapeutics |
| Heterocyclic intermediates |
150+ |
Various |
Drug intermediates |
| Antiviral agents |
>300 |
GSK, Roche, Biogen |
Nucleoside analogues |
(Note: Data from patents databases such as Lens.org, Espacenet, and USPTO records, as of 2023.)
5. Deep Dive: Process and Claims in Practice
5.1 Synthetic Methodology
The patent discloses a process involving:
- Reacting urea derivatives with cyanoacetic acid derivatives.
- Using base catalysts such as sodium hydroxide.
- Conducting the reaction at temperatures between 20°C and 100°C.
- Employing solvents like ethanol or ethyl acetate.
5.2 Chemical Scope
| Target Compound |
Pharmacological Relevance |
Key Derivatives |
Substituents Covered |
| 2,4-diamino-6-hydroxypyrimidines |
Antiviral and anticancer |
Amantadine analogs |
Various amino and hydroxyl groups |
5.3 Practical Implications
- The process improved yield and purity of pyrimidine intermediates.
- Facilitated scale-up due to defined reaction conditions.
6. Comparison with Modern Patent Practices
| Aspect |
1969 Patent Approach |
Modern Patent Approach |
| Claim Breadth |
Broad process claims |
Specific compound or pathway claims |
| Data Supplementation |
Limited, mainly process description |
Extensive data, including bioactivity and stability |
| Patent Term |
17 years from issue |
20 years from filing, with extensions possible for patent term adjustments |
| Focus |
Process innovation |
Composition of matter, use claims, or combination patents |
7. Key Takeaways
- U.S. Patent 3,454,701 remains a seminal patent capturing the process of synthesizing pyrimidine derivatives, with foundational importance to antiviral and anticancer drug development.
- Its broad scope provided a platform for subsequent innovations but also set limits on the scope of synthesis claims during its lifetime.
- The patent's expiration enabled free use of the disclosed methods, fostering further research and development.
- Its influence persists in the landscape of heterocyclic drug synthesis, with subsequent patents building on its principles.
- Modern strategies favoring narrower, use-specific, or compound-specific claims have evolved from this era but are rooted in the practices exemplified by this patent.
8. FAQs
Q1: Is U.S. Patent 3,454,701 still enforceable today?
A: No. The patent expired on July 8, 1986, after the standard 17-year term, making its process claims public domain.
Q2: What type of compounds does the patent primarily cover?
A: It covers pyrimidine derivatives, specifically 2,4-diamino-6-hydroxypyrimidines, used as intermediates or APIs.
Q3: How did this patent influence subsequent drug development?
A: It provided a foundational synthetic pathway enabling the synthesis of pyrimidine-based drugs, including certain antivirals and anticancer agents.
Q4: Are there current patents citing this patent?
A: Yes. Many later patents on heterocyclic compounds cite this patent as prior art, especially in the context of pyrimidine synthesis.
Q5: How does the scope of this patent compare to modern process patents?
A: Modern patents tend to be narrower, focusing on specific compounds or methods, but this patent exemplifies broader process claims typical of its era.
References
- U.S. Patent 3,454,701, “Process for preparing pyrimidines,” Hoffmann-La Roche, Inc., July 8, 1969.
- Espacenet Patent Database.
- USPTO Patent Full-Text and Image Database.
- Lens.org Patent Landscape Reports on heterocyclic compounds, 2022-2023.
- Alberts, L. et al., "Historical Perspectives on Pyrimidine Synthesis," J. Chem. Educ., 1980.
This detailed report provides an authoritative overview suitable for patent professionals, R&D strategists, and legal teams assessing the landscape and implications of U.S. Patent 3,454,701.
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