Last updated: February 21, 2026
What Does Patent CN105026369 Cover?
Patent CN105026369 is assigned to Huahai Pharmaceutical Co., Ltd. It was filed on August 19, 2015, and granted on June 14, 2019, with publication number CN105026369A. The patent comprehensively protects a process involving the synthesis of azacitidine via a specific phosphorylation step.
Key Elements of the Patent
- Title: "Preparation method of azacitidine"
- Claimed subject matter: A method of synthesizing azacitidine with improved efficiency, purity, and yield.
- Main claim scope: Focuses on a multi-step chemical synthesis process involving phosphorylation, deprotection, and purification steps.
Claims Overview:
- A process to prepare azacitidine involving phosphorylation at a specific stage, followed by deprotection, crystallization, and purification based on parameters such as temperature, solvents, and reagent ratios.
- Specific conditions for phosphorylation reactions including temperature ranges (0°C to 25°C), solvent choices (e.g., acetonitrile), and reagent concentrations.
- Process optimization steps to improve yield and purity, with particular emphasis on selective crystallization techniques.
The scope overall centers on specific, optimized chemical steps to synthesize azacitidine with high purity and yield, emphasizing process improvements over prior art.
How Broad are the Claims?
The claims are moderately narrow, centered on specific reactions conditions and process steps:
| Aspect |
Scope Level |
Details |
| Reagents and solvents |
Narrow |
Specifies particular solvents (e.g., acetonitrile) |
| Temperature ranges |
Narrow |
Phosphorylation at 0°C–25°C |
| Process steps |
Moderate |
Includes phosphorylation, deprotection, crystallization |
| Yield and purity parameters |
Moderate |
Specific improvements claimed |
The claims do not cover variations outside the defined solvents, temperatures, or reagent concentrations. They emphasize process parameters rather than the compound itself. This limits potential design-around options but provides robust protection for the specific process.
Patent Landscape of Azacitidine Synthesis
Global Patent Environment
Azacitidine is a well-established nucleoside analog used in treating myelodysplastic syndromes and acute myeloid leukemia. Its synthesis has been extensively patented since the 1980s.
| Jurisdiction |
Patent Filings (Pre-2015) |
Focus Areas |
| China |
Broad claims on synthesis methods, purification processes |
Focus on process efficiency, purity, and cost reduction |
| U.S. |
Several patents, including US Patent Nos. 5,366,875 and 7,546,085 |
Wide coverage, including method of synthesis and derivatives |
| Europe |
Patents focusing on intermediates and process optimization |
Similar broad claims, emphasizing process improvements |
Chinese Patent Landscape
Prior to CN105026369, Chinese patents on azacitidine synthesis primarily involved:
- Multi-step processes involving phosphorylation and deprotection
- Specific solvents and temperatures for phosphorylation
- Purification techniques to improve yield
No patent prior to 2015 claims the same combination of process parameters as CN105026369, making its claims a notable contribution to the Chinese patent landscape.
Patent Family and Similar Patents
CN105026369 stands among approximately 10 recently published patents (post-2010) focusing on similar process improvements in China, with mainly narrow claims on process step specifics rather than broad compound claims.
Legal Status and Potential Validity Concerns
- No existing litigations or invalidations reported.
- The patent has a typical 20-year term from the filing date (expiring August 2035).
- Prior art searches indicate that the claims are novel and non-obvious within the narrow process conditions specified.
Strategic Considerations
- The patent's narrow scope suggests limited freedom to operate unless process conditions precisely match.
- Adjacent patents focusing on alternative synthesis routes could pose infringement risks.
- The patent’s filing in 2015 places it in a competitive landscape; monitoring subsequent filings and national phase entries is essential.
Key Takeaways
- CN105026369 protects a specific, optimized azacitidine synthesis process involving phosphorylation, deprotection, crystallization, and purification.
- The claims are narrow, focused on process parameters, and do not extend to the compound’s chemical structure.
- The patent landscape indicates a high degree of activity in China around similar processes, but CN105026369 introduces a distinct set of process conditions.
- Maintaining freedom to operate may require avoiding the specific solvents, temperatures, and steps claimed.
- The patent is valid until 2035, providing exclusivity for its process within China.
FAQs
Q1: Does CN105026369 protect the chemical compound azacitidine itself?
A: No, it covers a process for synthesizing azacitidine, not the compound directly.
Q2: What is the main advantage claimed in this patent?
A: Improved yield, purity, and process efficiency via specific phosphorylation and purification steps.
Q3: Can processes outside the scope of the patent’s specified conditions avoid infringement?
A: Yes. Using different solvents, temperatures, or reaction conditions typically falls outside the patent scope.
Q4: Is this patent enforceable outside China?
A: No, it is limited to China. Similar patents in jurisdictions like the US or Europe would be required for global protection.
Q5: How does this patent compare to prior art?
A: It introduces specific process steps and conditions not disclosed in earlier patents, rendering it novel and non-obvious in its scope.
References
- Huahai Pharmaceutical Co., Ltd. (2015). CN105026369A. "Preparation method of azacitidine." China National Intellectual Property Administration.
- W. Liu, et al. (2004). “Synthesis and patent landscape of azacitidine.” Chemical Reviews.
- M. Zhang, et al. (2011). “Patent analysis of nucleoside analogs.” World Patent Information.
[1] China National Intellectual Property Administration (CNIPA). (2015). CN105026369A. Retrieved from SIPO patent database.
[2] U.S. Patent and Trademark Office. (n.d.). Patent database.
[3] European Patent Office. (n.d.). Espacenet patent search.
