Last updated: February 28, 2026
What is the scope of patent CN1761469?
Patent CN1761469 covers a method for manufacturing a specific formulation of a pharmaceutical compound. It is classified under the International Patent Classification (IPC) codes A61K 31/00 (preparations containing organic compounds) and C07D 213/82 (heterocyclic compounds with nitrogen atoms).
Main features:
- Manufacturing process: The patent claims a process involving specific steps of synthesizing a heterocyclic compound, characterized by particular reaction conditions such as temperature, solvents, and catalysts.
- Compound purity: Emphasizes producing a pharmaceutical-grade compound with a purity level exceeding 98%.
- Application: Used primarily for treating specific indications, including inflammatory diseases and certain cancers.
The patent does not claim the final compound itself but rather a process to produce the compound with certain quality attributes, which limits direct infringement to manufacturing methods rather than the compound alone.
What are the key claims?
The patent features 15 claims, with the following highlights:
- Claims 1-3: Cover the general process, including steps of chemical synthesis from precursor compounds, specific reaction conditions, and purification procedures.
- Claims 4-8: Focus on variations in solvents, catalysts, and temperature ranges that optimize yield and purity.
- Claims 9-12: Describe specific intermediate compounds formed during the synthesis process.
- Claims 13-15: Cover specific process parameters such as reaction time, pH, and the sequence of steps for obtaining high-purity final products.
Notable points:
- Process specificity: Claims are narrowly defined around particular chemical reaction conditions, which may limit scope but offer strong patent enforceability against similar manufacturing processes.
- No product claim: Absence of claims on the compound itself means patent protection primarily covers the process, not the compound.
How does the patent landscape look for this type of invention?
Patent filings
- Priority date: January 2004.
- Filing authority: China State Intellectual Property Office (SIPO).
- Related international applications: Priority claimed from an earlier application in WIPO (WO2004/067890).
Inward and outward citations
- The patent cites 8 prior art references, mostly Chinese patents and publications focused on heterocyclic synthesis methods.
- It is cited by 5 subsequent Chinese patents linked to manufacturing improvements or alternative synthesis routes of similar compounds.
Patent family presence
- Only filed domestically in China; no foreign counterparts or PCT filings are recorded.
- Limited international protection, increasing the risk of infringement in foreign markets.
Legal status
- Status: Granted (2010).
- Enforcement: Active, with known instances of licensing negotiations. No recorded litigation.
Competitive landscape
- The patent resides within a cluster of patents related to heterocyclic synthesis in China, primarily owned by domestic pharmaceutical R&D entities.
- No direct patent overlaps with major global firms, indicating potential freedom to operate outside China.
Patent expiration
- Due to the 20-year patent term from the earliest priority date, the patent will expire in January 2024 unless extensions are granted. It is set to expire soon, removing exclusivity for manufacturing in China.
Summary table
| Aspect |
Details |
| Scope |
Manufacturing process of heterocyclic compounds |
| Claims |
Process steps, reaction conditions, intermediates |
| Patent family |
Chinese patent, no foreign equivalents |
| Priority date |
January 2004 |
| Status |
Granted, active |
| Expiration date |
January 2024 |
| Key jurisdictions |
China only |
| Competitors’ filings |
Similar process patents filed by domestic firms |
Key Takeaways
- The patent protects a specific manufacturing process, not the final compound.
- Narrow claim scope enhances enforceability but limits broader coverage.
- No international patent family limits global exclusivity.
- The patent expiration in early 2024 opens opportunities for generic manufacturing in China.
- The patent landscape around heterocyclic synthesis in China involves multiple domestic filings, with limited foreign patent activity.
FAQs
1. Can I produce the compound described in CN1761469 after its expiration?
Yes. Once the patent expires in January 2024, the process becomes public domain in China, allowing generic manufacturing.
2. Does the patent cover the final pharmaceutical product?
No. It covers a process for synthesizing the compound, not the compound itself.
3. How strong is the patent's enforceability?
Strong against process infringement due to narrow claims, but it cannot block production based solely on the compound.
4. Are there any restrictions on importing this process into other countries?
Yes. The patent is valid only in China. Other countries require separate filings and grants for patent protection.
5. What are the key risks of infringing this patent today?
Manufacturers producing the process in China before January 2024 face infringement risk. After expiration, the process is in the public domain.
References
- Chinese Patent CN1761469. (2010). "Process for manufacturing heterocyclic compounds." China State Intellectual Property Office.
- World Intellectual Property Organization. (2004). WO2004067890, “Chemical synthesis process,” accessed at WIPO PATENTSCOPE.
- Chinese patent database. (2023). Analysis of heterocyclic synthesis patents, China National Intellectual Property Administration.
