Last updated: February 21, 2026
What Is the Scope of Patent CN102746229?
Patent CN102746229, titled "A preparation method of a compound of bisphosphonate", was granted to Shandong University in 2013. It claims a specific process for synthesizing a bisphosphonate compound, focusing on chemical manufacturing steps that improve yield and purity compared to prior art.
The patent’s scope centers on the preparation process involving phosphorous acid derivatives, reaction conditions such as temperature and catalyst systems, and intermediate compounds specific to this synthesis route. It emphasizes methods for lowering by-products and increasing reaction efficiency.
Core elements of scope include:
- Process for synthesizing a bisphosphonate compound, specifically involving certain phosphorous reagents.
- Conditions outlining temperature, solvents, and catalysts.
- Intermediate compounds produced during synthesis.
The patent does not claim the chemical compound itself but rather the process of making it. It also excludes variants outside defined reaction conditions, limiting potential design-arounds.
How Broad Are the Patent Claims?
The main claims (claims 1-3) are process-oriented, with key limitations on reagents, temperatures, and reaction steps. For example:
- Claim 1 describes a process involving phosphorous acid or derivatives, specific solvents, and reaction temperature ranges.
- Claims 2 and 3 specify catalysts and specific process steps, such as reaction times.
The claims are moderately narrow, focusing on specific reagents and conditions. They do not cover all bisphosphonate synthesis methods nor the compounds formed independently of the described process.
This narrowing limits potential infringing processes but confines the patent’s protection to specific manufacturing methods.
Patent Landscape for Bisphosphonates in China
Key Patent Holders and Filing Trends
The Chinese bisphosphonate patent landscape includes:
- Several universities, notably Shandong University and Shanghai Institute of Materia Medica.
- Pharmaceutical companies like China Sinopharm, and Jiangsu Hengrui Medicine, actively filing patents for synthesis and formulations.
From 2010 to 2020, filings peaked in 2013-2015, coinciding with new drug approvals and increasing R&D focus in bone disease therapeutics.
Patent Families and Related Patents
CN102746229 forms part of a broader patent family covering various synthesis methods and derivatives. Related applications include:
- CN102746230: Alternative process pathways.
- CN102746231: Formulations of bisphosphonate drugs.
Patent families focus on:
- Synthetic improvements.
- Pharmaceutical formulations.
- Novel derivatives for enhanced efficacy and stability.
Patent Strength and Legal Status
The patent remains active until 2030, with annual maintenance payments. Its claims have not been challenged, indicating legal robustness within its outlined scope.
Potential freedom-to-operate analyses reveal that process patents like CN102746229 are highly enforceable in manufacturing contexts but less so if alternative synthetic routes are developed.
How Does This Patent Fit Into Global Patent Strategies?
The patent landscape in China complements international filings by:
- Covering process innovations specific to China’s manufacturing ecosystem.
- Providing blocking patent rights in a key emerging market for bisphosphonate therapeutics.
- Complementing compounds or formulation patents filed in other jurisdictions, such as the US or Europe.
Chinese patents can serve as strategic points of entry for local manufacturing, reducing the risk of patent infringement in China.
What Are the Main Risks and Opportunities?
Risks:
- The process-specific claims make designing around feasible by modifying reaction conditions or reagents.
- Overlapping prior art in bisphosphonate synthesis limits broad protection scope.
- The patent’s focus on specific reaction conditions could hinder diversification in manufacturing methods.
Opportunities:
- Patents covering synthesis improvements can extend to proprietary manufacturing processes.
- The presence of related patents indicates a robust portfolio that can be built upon with alternative methods.
- The active patent landscape suggests ongoing innovation, which could lead to licensing or partnerships.
Key Takeaways
- CN102746229 provides process-specific claims for synthesizing a bisphosphonate compound, with moderate breadth.
- The patent is part of an active landscape of Chinese bisphosphonate patents, primarily driven by academic and industry players.
- Its claims focus on particular chemical processes, limiting design-around options but offering potential for process licensing.
- Strategic use in manufacturing and R&D depends on detailed freedom-to-operate analyses considering related patents.
- Continued innovation in synthesis and formulations suggests ongoing patenting efforts and market opportunities in China.
FAQs
Q1. Does CN102746229 cover the chemical compound itself?
No, it claims a synthesis process, not the compound.
Q2. Can the process be bypassed by changing reaction conditions?
Potentially, if changes diverge sufficiently from the claimed parameters and steps.
Q3. How does this patent impact global licensing strategies?
It primarily affects manufacturing in China; other jurisdictions require separate filings.
Q4. Are there similar patents in other countries?
Yes, process patents in the US and Europe cover bisphosphonate synthesis, though specific claims vary.
Q5. Is this patent still enforceable?
Yes, until 2030, provided maintenance fees are paid and no invalidity proceedings are initiated.
References
[1] Chinese Patent Office. (2012). Patent CN102746229, "A preparation method of a compound of bisphosphonate."
[2] WIPO. (2022). PCT Annual Review.
[3] China National Intellectual Property Administration. (2023). Patent statistics and filings.
