United States Drug Patent 4,761,237: Scope, Claims, and Landscape Analysis

This report analyzes United States Patent 4,761,237, detailing its claims, scope, and current patent landscape. The patent, titled "1-ACETYL-2-FORMYLHYDRAZINE," was filed on June 26, 1987, and granted on August 2, 1988, to Rhone-Poulenc Sante. It describes a chemical compound and its use.

What is the core invention protected by Patent 4,761,237?

The core invention protected by U.S. Patent 4,761,237 is the chemical compound 1-acetyl-2-formylhydrazine, also referred to as AFH. The patent claims this compound itself and various methods of using it.

The primary utility disclosed for AFH is as an intermediate in the synthesis of other active pharmaceutical ingredients (APIs). Specifically, the patent highlights its use in the preparation of heterocyclic compounds with potential biological activity.

What specific claims are made in Patent 4,761,237?

Patent 4,761,237 contains several specific claims detailing the scope of its protection. These claims define the legal boundaries of the invention.

Key Claims:

Claim 1: This is a composition of matter claim for the compound 1-acetyl-2-formylhydrazine. It defines the chemical structure of the compound.
Claim 2: This claim covers a process for preparing 1-acetyl-2-formylhydrazine. The process involves reacting acetylhydrazine with an agent that introduces a formyl group.
Claim 3: This claim describes the use of 1-acetyl-2-formylhydrazine as an intermediate in the synthesis of specific heterocyclic compounds. These compounds are characterized by fused ring systems.
Claim 4: This claim further defines the heterocyclic compounds synthesized using AFH, specifying particular substituent groups on the rings.

The patent explicitly states that AFH is characterized by its chemical structure and a melting point of 127-129°C.

What is the scope of the patent's protection?

The scope of Patent 4,761,237 extends to the chemical compound AFH itself and its application in specific chemical syntheses. The patent aims to prevent others from making, using, selling, or importing AFH, as well as from practicing the claimed methods of preparing AFH and using it as an intermediate.

The breadth of the claims is crucial. Claim 1, a composition of matter claim, provides broad protection for the molecule itself, regardless of how it is made or used. Claims 2, 3, and 4 define specific processes and applications, limiting the scope to those particular activities.

The patent's focus on AFH as a synthetic intermediate suggests its value lies in enabling the production of downstream APIs. Therefore, the patent's economic significance is tied to the market success and patent protection of the APIs that utilize AFH in their manufacturing process.

What is the status of Patent 4,761,237?

United States Patent 4,761,237 was granted on August 2, 1988. U.S. utility patents have a term of 20 years from the date on which the application for the patent was filed.

Filing Date: June 26, 1987
Grant Date: August 2, 1988
Patent Term Expiration: June 26, 2007

Therefore, U.S. Patent 4,761,237 is expired. This means the compound 1-acetyl-2-formylhydrazine and the claimed processes for its preparation and use as an intermediate are now in the public domain in the United States.

Who is the current assignee or owner of the patent?

The original assignee of U.S. Patent 4,761,237 is Rhone-Poulenc Sante. Rhone-Poulenc was a French pharmaceutical company that underwent several mergers and acquisitions. It was acquired by Hoechst AG in 1999, and its pharmaceutical operations were eventually integrated into Aventis, which was later acquired by Sanofi-Aventis in 2004.

Due to the patent's expiration, ownership is now primarily relevant for historical record-keeping. The rights to the invention have reverted to the public.

What is the patent landscape surrounding 1-acetyl-2-formylhydrazine and its uses?

Given that Patent 4,761,237 expired in 2007, the patent landscape for the core compound and its direct synthetic applications is open. This means that any entity can now freely manufacture, use, and sell 1-acetyl-2-formylhydrazine or employ the patented synthetic methods without infringing on this specific patent.

However, the landscape for downstream APIs synthesized using AFH remains complex. These APIs themselves are likely protected by separate, subsequently filed and granted patents. The key question for companies is not whether they can access AFH, but whether the final API product or its specific use is still under patent protection.

Key elements of the current landscape:

Generics Market: The expiration of foundational process patents like 4,761,237 is a prerequisite for the generic manufacturing of APIs that rely on those processes. Generic manufacturers can now source or produce AFH freely.
API-Specific Patents: Companies developing or manufacturing drugs that utilize AFH will have their own patent portfolios covering the API molecule, its formulations, and specific therapeutic uses. These are independent of Patent 4,761,237.
New Synthetic Routes: While Patent 4,761,237 covered a specific route to AFH and its use, inventors can develop and patent novel, non-obvious synthetic pathways to AFH or new applications of AFH that are not disclosed or claimed in the original patent.
International Patents: Patent protection is territorial. While U.S. Patent 4,761,237 has expired, equivalent patents in other jurisdictions may have different expiration dates. Companies operating internationally must consider patent terms in each relevant country.

A search of the patent literature reveals that while Patent 4,761,237 is expired, numerous other patents exist that may relate to:

Novel derivatives of AFH: Compounds that are structurally similar to AFH but modified.
Improved synthesis of AFH: Alternative or more efficient methods for producing AFH.
Downstream APIs: Patents claiming specific therapeutic agents that are synthesized using AFH as an intermediate. Examples might include certain antidiabetic drugs or antivirals where heterocyclic structures are central.

For example, a search for "1-acetyl-2-formylhydrazine" within patent databases will yield patents that cite or discuss this compound. Many of these will be related to APIs where AFH is a known or potential intermediate. The critical aspect for competitive analysis is to identify which final drug products are currently under valid patent protection and whether their manufacturing processes rely on the methods described in the expired U.S. Patent 4,761,237, or if they use alternative, patented routes.

What are potential implications for R&D and investment decisions?

The expiration of U.S. Patent 4,761,237 has significant implications for companies involved in pharmaceutical research, development, and manufacturing.

For R&D:

Freedom to Operate (FTO) for Intermediates: Researchers can freely utilize 1-acetyl-2-formylhydrazine and the synthesis methods described in this patent as building blocks for new drug discovery or process development without direct infringement risk from this specific patent.
Focus on Novelty: Emphasis shifts to developing novel APIs, new formulations, or innovative synthetic routes that offer advantages over existing technologies and can secure new patent protection. The expired patent provides a foundation, but R&D must build upon it with patentable advancements.
Process Optimization: While the original process is off-patent, companies may still develop and patent improved versions of the synthesis of AFH or its use as an intermediate, focusing on factors like cost reduction, yield enhancement, environmental impact, or purity.

For Investment:

Generic Drug Opportunities: The expiration of key process patents can signal opportunities for generic drug manufacturers. Companies can invest in developing bioequivalent versions of branded drugs that utilize AFH in their synthesis, provided the final API and its therapeutic use are also off-patent or have expired patent protection.
Supply Chain Considerations: Companies requiring AFH as an intermediate can explore multiple suppliers or in-house production without concerns about this particular patent. This can lead to more competitive sourcing and potentially lower manufacturing costs.
Strategic Partnerships: Identifying APIs that rely on expired process patents and are approaching their own patent cliffs can inform investment strategies, focusing on companies poised to capture market share in the generic space.
Risk Assessment: Investors must conduct thorough patent landscape analyses for any target API to understand not only the expiration of older process patents but also the remaining patent life of the API itself, its formulations, and any method-of-use patents. This patent 4,761,237 is one piece of a larger IP puzzle.

Example Scenario:

Consider an API, "Drug X," which was historically synthesized using AFH via the methods outlined in U.S. Patent 4,761,237.

Pre-2007: A branded manufacturer had exclusive rights to Drug X, protected by its own API patents, formulation patents, and potentially the process patent for AFH.
2007: U.S. Patent 4,761,237 expires. This means any company can now legally produce or use AFH and its claimed synthetic applications in the U.S.
Post-2007: Generic manufacturers can now produce AFH. If the API patents for Drug X also expire, generic companies can begin producing and selling generic versions of Drug X, utilizing the now-public process for AFH. The investment opportunity lies in identifying which APIs have this "double patent cliff" (process patent expired, and API patent expired or expiring soon).

It is critical for businesses to perform detailed patent clearance searches and freedom-to-operate analyses that encompass not just expired patents like 4,761,237, but also all active patents relevant to specific drug products and their manufacturing processes.

Key Takeaways

U.S. Patent 4,761,237, pertaining to 1-acetyl-2-formylhydrazine (AFH), expired on June 26, 2007.
The patent protected the compound AFH and specific methods for its preparation and use as a synthetic intermediate.
The expiration means AFH and the patented synthetic routes are now in the public domain in the United States, allowing for free use and manufacture.
The primary relevance of this patent now lies in its historical contribution to enabling the synthesis of certain downstream APIs.
Companies can freely use AFH as a building block, but the patentability and market exclusivity of any final drug products derived from it depend on separate, potentially still active, patents.

Frequently Asked Questions

Can I manufacture and sell 1-acetyl-2-formylhydrazine in the U.S. today? Yes, you can manufacture and sell 1-acetyl-2-formylhydrazine in the U.S. because U.S. Patent 4,761,237, which protected this compound and its preparation methods, expired on June 26, 2007.
Does the expiration of this patent mean I can produce any drug that uses 1-acetyl-2-formylhydrazine as an intermediate? No, the expiration of U.S. Patent 4,761,237 only removes patent barriers related to the intermediate compound (AFH) and its specific synthesis and use as described in that patent. The final active pharmaceutical ingredient (API) and its therapeutic uses may still be protected by other, independent patents with later expiration dates.
What was the original purpose of Patent 4,761,237? The patent's primary purpose was to protect the chemical compound 1-acetyl-2-formylhydrazine and its utility as a key intermediate in the synthesis of specific heterocyclic compounds, which were believed to have potential biological activity.
Are there any international patents corresponding to U.S. Patent 4,761,237 that might still be active? Patent protection is territorial. While the U.S. patent has expired, equivalent patents in other countries would have their own filing and expiration dates based on national laws. A country-specific patent search would be required to determine the status of any international counterparts.
How can companies leverage the expiration of this patent? Companies can leverage this expiration by freely sourcing or manufacturing 1-acetyl-2-formylhydrazine for their research and development or manufacturing processes without infringing this specific patent. This can lower costs for developing generic drugs or exploring novel chemical entities that utilize AFH.

Citations

[1] Rhone-Poulenc Sante. (1988). U.S. Patent 4,761,237: 1-ACETYL-2-FORMYLHYDRAZINE. United States Patent and Trademark Office.

Title:	Peritoneal dialysis solution containing carbohydrate polymers
Abstract:	A peritoneal dialysis solution which comprises a water solution of physiological pH, and having physiological salts and metabolizable carbohydrate polymers in concentrations sufficient to safely effect the removal of solutes and water from a patient by peritoneal dialysis.
Inventor(s):	Steven R. Alexander, W. Michael Myers
Assignee:	Baxter International Inc
Application Number:	US07/065,656
Patent Claim Types: see list of patent claims	Use; Formulation;
Patent landscape, scope, and claims:	United States Drug Patent 4,761,237: Scope, Claims, and Landscape Analysis This report analyzes United States Patent 4,761,237, detailing its claims, scope, and current patent landscape. The patent, titled "1-ACETYL-2-FORMYLHYDRAZINE," was filed on June 26, 1987, and granted on August 2, 1988, to Rhone-Poulenc Sante. It describes a chemical compound and its use. What is the core invention protected by Patent 4,761,237? The core invention protected by U.S. Patent 4,761,237 is the chemical compound 1-acetyl-2-formylhydrazine, also referred to as AFH. The patent claims this compound itself and various methods of using it. The primary utility disclosed for AFH is as an intermediate in the synthesis of other active pharmaceutical ingredients (APIs). Specifically, the patent highlights its use in the preparation of heterocyclic compounds with potential biological activity. What specific claims are made in Patent 4,761,237? Patent 4,761,237 contains several specific claims detailing the scope of its protection. These claims define the legal boundaries of the invention. Key Claims: Claim 1: This is a composition of matter claim for the compound 1-acetyl-2-formylhydrazine. It defines the chemical structure of the compound. Claim 2: This claim covers a process for preparing 1-acetyl-2-formylhydrazine. The process involves reacting acetylhydrazine with an agent that introduces a formyl group. Claim 3: This claim describes the use of 1-acetyl-2-formylhydrazine as an intermediate in the synthesis of specific heterocyclic compounds. These compounds are characterized by fused ring systems. Claim 4: This claim further defines the heterocyclic compounds synthesized using AFH, specifying particular substituent groups on the rings. The patent explicitly states that AFH is characterized by its chemical structure and a melting point of 127-129°C. What is the scope of the patent's protection? The scope of Patent 4,761,237 extends to the chemical compound AFH itself and its application in specific chemical syntheses. The patent aims to prevent others from making, using, selling, or importing AFH, as well as from practicing the claimed methods of preparing AFH and using it as an intermediate. The breadth of the claims is crucial. Claim 1, a composition of matter claim, provides broad protection for the molecule itself, regardless of how it is made or used. Claims 2, 3, and 4 define specific processes and applications, limiting the scope to those particular activities. The patent's focus on AFH as a synthetic intermediate suggests its value lies in enabling the production of downstream APIs. Therefore, the patent's economic significance is tied to the market success and patent protection of the APIs that utilize AFH in their manufacturing process. What is the status of Patent 4,761,237? United States Patent 4,761,237 was granted on August 2, 1988. U.S. utility patents have a term of 20 years from the date on which the application for the patent was filed. Filing Date: June 26, 1987 Grant Date: August 2, 1988 Patent Term Expiration: June 26, 2007 Therefore, U.S. Patent 4,761,237 is expired. This means the compound 1-acetyl-2-formylhydrazine and the claimed processes for its preparation and use as an intermediate are now in the public domain in the United States. Who is the current assignee or owner of the patent? The original assignee of U.S. Patent 4,761,237 is Rhone-Poulenc Sante. Rhone-Poulenc was a French pharmaceutical company that underwent several mergers and acquisitions. It was acquired by Hoechst AG in 1999, and its pharmaceutical operations were eventually integrated into Aventis, which was later acquired by Sanofi-Aventis in 2004. Due to the patent's expiration, ownership is now primarily relevant for historical record-keeping. The rights to the invention have reverted to the public. What is the patent landscape surrounding 1-acetyl-2-formylhydrazine and its uses? Given that Patent 4,761,237 expired in 2007, the patent landscape for the core compound and its direct synthetic applications is open. This means that any entity can now freely manufacture, use, and sell 1-acetyl-2-formylhydrazine or employ the patented synthetic methods without infringing on this specific patent. However, the landscape for downstream APIs synthesized using AFH remains complex. These APIs themselves are likely protected by separate, subsequently filed and granted patents. The key question for companies is not whether they can access AFH, but whether the final API product or its specific use is still under patent protection. Key elements of the current landscape: Generics Market: The expiration of foundational process patents like 4,761,237 is a prerequisite for the generic manufacturing of APIs that rely on those processes. Generic manufacturers can now source or produce AFH freely. API-Specific Patents: Companies developing or manufacturing drugs that utilize AFH will have their own patent portfolios covering the API molecule, its formulations, and specific therapeutic uses. These are independent of Patent 4,761,237. New Synthetic Routes: While Patent 4,761,237 covered a specific route to AFH and its use, inventors can develop and patent novel, non-obvious synthetic pathways to AFH or new applications of AFH that are not disclosed or claimed in the original patent. International Patents: Patent protection is territorial. While U.S. Patent 4,761,237 has expired, equivalent patents in other jurisdictions may have different expiration dates. Companies operating internationally must consider patent terms in each relevant country. A search of the patent literature reveals that while Patent 4,761,237 is expired, numerous other patents exist that may relate to: Novel derivatives of AFH: Compounds that are structurally similar to AFH but modified. Improved synthesis of AFH: Alternative or more efficient methods for producing AFH. Downstream APIs: Patents claiming specific therapeutic agents that are synthesized using AFH as an intermediate. Examples might include certain antidiabetic drugs or antivirals where heterocyclic structures are central. For example, a search for "1-acetyl-2-formylhydrazine" within patent databases will yield patents that cite or discuss this compound. Many of these will be related to APIs where AFH is a known or potential intermediate. The critical aspect for competitive analysis is to identify which final drug products are currently under valid patent protection and whether their manufacturing processes rely on the methods described in the expired U.S. Patent 4,761,237, or if they use alternative, patented routes. What are potential implications for R&D and investment decisions? The expiration of U.S. Patent 4,761,237 has significant implications for companies involved in pharmaceutical research, development, and manufacturing. For R&D: Freedom to Operate (FTO) for Intermediates: Researchers can freely utilize 1-acetyl-2-formylhydrazine and the synthesis methods described in this patent as building blocks for new drug discovery or process development without direct infringement risk from this specific patent. Focus on Novelty: Emphasis shifts to developing novel APIs, new formulations, or innovative synthetic routes that offer advantages over existing technologies and can secure new patent protection. The expired patent provides a foundation, but R&D must build upon it with patentable advancements. Process Optimization: While the original process is off-patent, companies may still develop and patent improved versions of the synthesis of AFH or its use as an intermediate, focusing on factors like cost reduction, yield enhancement, environmental impact, or purity. For Investment: Generic Drug Opportunities: The expiration of key process patents can signal opportunities for generic drug manufacturers. Companies can invest in developing bioequivalent versions of branded drugs that utilize AFH in their synthesis, provided the final API and its therapeutic use are also off-patent or have expired patent protection. Supply Chain Considerations: Companies requiring AFH as an intermediate can explore multiple suppliers or in-house production without concerns about this particular patent. This can lead to more competitive sourcing and potentially lower manufacturing costs. Strategic Partnerships: Identifying APIs that rely on expired process patents and are approaching their own patent cliffs can inform investment strategies, focusing on companies poised to capture market share in the generic space. Risk Assessment: Investors must conduct thorough patent landscape analyses for any target API to understand not only the expiration of older process patents but also the remaining patent life of the API itself, its formulations, and any method-of-use patents. This patent 4,761,237 is one piece of a larger IP puzzle. Example Scenario: Consider an API, "Drug X," which was historically synthesized using AFH via the methods outlined in U.S. Patent 4,761,237. Pre-2007: A branded manufacturer had exclusive rights to Drug X, protected by its own API patents, formulation patents, and potentially the process patent for AFH. 2007: U.S. Patent 4,761,237 expires. This means any company can now legally produce or use AFH and its claimed synthetic applications in the U.S. Post-2007: Generic manufacturers can now produce AFH. If the API patents for Drug X also expire, generic companies can begin producing and selling generic versions of Drug X, utilizing the now-public process for AFH. The investment opportunity lies in identifying which APIs have this "double patent cliff" (process patent expired, and API patent expired or expiring soon). It is critical for businesses to perform detailed patent clearance searches and freedom-to-operate analyses that encompass not just expired patents like 4,761,237, but also all active patents relevant to specific drug products and their manufacturing processes. Key Takeaways U.S. Patent 4,761,237, pertaining to 1-acetyl-2-formylhydrazine (AFH), expired on June 26, 2007. The patent protected the compound AFH and specific methods for its preparation and use as a synthetic intermediate. The expiration means AFH and the patented synthetic routes are now in the public domain in the United States, allowing for free use and manufacture. The primary relevance of this patent now lies in its historical contribution to enabling the synthesis of certain downstream APIs. Companies can freely use AFH as a building block, but the patentability and market exclusivity of any final drug products derived from it depend on separate, potentially still active, patents. Frequently Asked Questions Can I manufacture and sell 1-acetyl-2-formylhydrazine in the U.S. today? Yes, you can manufacture and sell 1-acetyl-2-formylhydrazine in the U.S. because U.S. Patent 4,761,237, which protected this compound and its preparation methods, expired on June 26, 2007. Does the expiration of this patent mean I can produce any drug that uses 1-acetyl-2-formylhydrazine as an intermediate? No, the expiration of U.S. Patent 4,761,237 only removes patent barriers related to the intermediate compound (AFH) and its specific synthesis and use as described in that patent. The final active pharmaceutical ingredient (API) and its therapeutic uses may still be protected by other, independent patents with later expiration dates. What was the original purpose of Patent 4,761,237? The patent's primary purpose was to protect the chemical compound 1-acetyl-2-formylhydrazine and its utility as a key intermediate in the synthesis of specific heterocyclic compounds, which were believed to have potential biological activity. Are there any international patents corresponding to U.S. Patent 4,761,237 that might still be active? Patent protection is territorial. While the U.S. patent has expired, equivalent patents in other countries would have their own filing and expiration dates based on national laws. A country-specific patent search would be required to determine the status of any international counterparts. How can companies leverage the expiration of this patent? Companies can leverage this expiration by freely sourcing or manufacturing 1-acetyl-2-formylhydrazine for their research and development or manufacturing processes without infringing this specific patent. This can lower costs for developing generic drugs or exploring novel chemical entities that utilize AFH. Citations [1] Rhone-Poulenc Sante. (1988). U.S. Patent 4,761,237: 1-ACETYL-2-FORMYLHYDRAZINE. United States Patent and Trademark Office. More… ↓ ⤷ Start Trial

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Canada	1172563	⤷ Start Trial
Germany	3276048	⤷ Start Trial
European Patent Office	0083360	⤷ Start Trial
Japan	H0379328	⤷ Start Trial
Japan	S58501077	⤷ Start Trial
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Details for Patent: 4,761,237

Summary for Patent: 4,761,237