United States Patent 3,883,545: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 3,883,545, titled "Certain 1-hydroxy-2-pyridones," was granted on May 13, 1975, to inventors Gerhard Lohaus and Walter Dittmar, assigned to Hoechst Aktiengesellschaft. This patent is significant for its contribution to the field of antimycotic compounds and their synthesis.
Background and Prior Art
Before the invention described in US 3,883,545, hydroxy-pyridones were known but had limitations. The prior art hydroxy-pyridones, particularly those carrying only one methyl group in the 4 or 6 position, had inferior antimycotic properties compared to the compounds described in this patent[1].
Claims and Scope
The patent includes nine claims that define the scope of the invention. Here are the key aspects:
Chemical Structure
The claims cover 1-hydroxy-2-pyridones with specific substitutions. The general formula includes:
- R₁ as alkyl of 1 to 17 carbon atoms, cycloalkyl of 5 to 7 carbon atoms, cyclohexylalkyl, or phenalkyl with 1 to 3 carbon atoms in the alkylene chain, or α-furyl, which may be substituted by halogen.
- R₂ to R₄ as hydrogen or lower alkyl, or two adjacent substituents together forming a trimethylene or tetramethylene chain.
- The requirement that R₁ to R₄ together contain at least 2 carbon atoms[1].
Synthesis Method
The process involves contacting unsaturated β-keto-esters with hydroxylamine or its acid addition salts and subjecting the products to cyclization in an acid or alkaline medium at temperatures from 0 to 150°C[1].
Antimycotic Properties
The compounds obtained through this process exhibit good antimycotic properties, making them useful medicaments against dermatomycoses. They are effective against various pathogens, including dermatophytes, Candida, and more dangerous pathogens like Cryptococcus neoformans and Blastomyces dermatitidis[1].
Superiority Over Prior Art
The compounds of claim 2 are substantially superior to the hydroxy-pyridones carrying only one methyl group in the 4 or 6 position, as known from US Patent No. 3,269,904. This superiority is due to their enhanced antimycotic properties[1].
Patent Landscape
Related Patents
The patent is part of a series of continuations and continuations-in-part, similar to the structure seen in other patent families. For example, the patent is a continuation-in-part of Ser. No. 851,428, Aug. 19, 1969, abandoned, and Ser. No. 199,320, Nov. 6, 1970, abandoned[1].
Global Impact
Given the international nature of pharmaceutical research, patents like US 3,883,545 are often part of a global patent family. Tools like the Global Dossier provided by the USPTO can help track related applications filed at participating IP Offices, including the IP5 Offices[4].
Claim Coverage and Scope Concepts
To analyze the patent landscape effectively, it is crucial to categorize patents by claims and scope concepts. This approach helps in understanding which patents and claims are actively protecting the intellectual property and where gaps or opportunities exist. Tools like ClaimScape® software can generate interactive claim charts to facilitate this analysis[3].
Patent Analytics
Patent analytics plays a vital role in managing and understanding the patent portfolio. By tracking patents by claims and scope concepts, companies can identify which patents cover their products and technologies, and where there are gaps in coverage. This helps in making informed decisions about patent maintenance and future development strategies[3].
Legal and Regulatory Considerations
Patents like US 3,883,545 must navigate various legal and regulatory hurdles. Issues such as obviousness-type double patenting (ODP) and patent term adjustments (PTA) can affect the validity and term of the patent. The Federal Circuit has addressed such issues in cases like In re Cellect, LLC, highlighting the importance of careful patent prosecution and management[2].
Public Access and Search Facilities
The USPTO provides several resources for searching and analyzing patents, including the Public Search Facility, Patent and Trademark Resource Centers (PTRCs), and the Electronic Official Gazette. These resources are essential for stakeholders to understand the patent landscape and conduct thorough searches[4].
Future Directions and Opportunities
The study and analysis of patents like US 3,883,545 can highlight future design opportunities and areas for innovation. By using claim charts and scope concepts, companies can identify potential gaps in their current coverage and plan for future developments. This proactive approach can help in maintaining a strong and relevant patent portfolio[3].
Key Takeaways
- Chemical Structure and Synthesis: The patent covers specific 1-hydroxy-2-pyridones with defined substitutions and a novel synthesis method.
- Antimycotic Properties: The compounds have superior antimycotic properties compared to prior art.
- Patent Landscape: The patent is part of a broader global patent family and requires careful management using patent analytics tools.
- Legal Considerations: The patent must comply with legal and regulatory requirements, including ODP and PTA.
- Future Directions: Analyzing the patent can reveal opportunities for future innovation and gap filling in the patent portfolio.
FAQs
What are the key claims of US 3,883,545?
The key claims cover the specific chemical structure of 1-hydroxy-2-pyridones, the synthesis method involving unsaturated β-keto-esters and hydroxylamine, and the resulting antimycotic properties.
How do the compounds of US 3,883,545 differ from prior art?
The compounds are substantially superior to prior art hydroxy-pyridones carrying only one methyl group in the 4 or 6 position due to their enhanced antimycotic properties.
What tools can be used to analyze the patent landscape of US 3,883,545?
Tools such as ClaimScape® software, Global Dossier, and the USPTO's Public Search Facility can be used to analyze the patent landscape and identify gaps or opportunities.
What legal considerations are important for patents like US 3,883,545?
Patents must comply with regulations regarding obviousness-type double patenting (ODP) and patent term adjustments (PTA), among other legal considerations.
How can companies use patent analytics to benefit from patents like US 3,883,545?
Companies can use patent analytics to track patents by claims and scope concepts, identify gaps in coverage, and plan for future developments, thereby maintaining a strong and relevant patent portfolio.
Cited Sources
- US3883545A - Certain 1-hydroxy-2-pyridones - Google Patents
- In re Cellect - United States Court of Appeals for the Federal Circuit
- Patent Analytics | Intellectual Property Law - SLWIP
- Search for patents - USPTO - USPTO
