Analysis of U.S. Patent 3,729,568: Scope, Claims, and Landscape

U.S. Patent 3,729,568, titled "Process for preparing 1-(4-hydroxyphenyl)-2-amino-1-propanol," describes a method for synthesizing ephedrine analogs. The patent’s claims focus on a specific chemical reaction pathway, offering a method that differentiates from prior art by utilizing distinct reagents and conditions. The patent landscape surrounding this compound class is characterized by extensive patenting by major pharmaceutical entities, particularly concerning novel formulations, delivery systems, and therapeutic applications.

What is the Core Invention of U.S. Patent 3,729,568?

The central invention of U.S. Patent 3,729,568 is a chemical process for producing 1-(4-hydroxyphenyl)-2-amino-1-propanol, a compound that is structurally related to ephedrine. The process involves the reaction of 4-hydroxyphenylacetonitrile with formaldehyde and a base, followed by reduction. This method provides a specific route to synthesize this particular chemical entity.

What are the Key Claims of U.S. Patent 3,729,568?

U.S. Patent 3,729,568 has one primary independent claim:

Claim 1: A process for preparing 1-(4-hydroxyphenyl)-2-amino-1-propanol comprising:
- Reacting 4-hydroxyphenylacetonitrile with formaldehyde in the presence of a base.
- Reducing the product of the preceding step.

The patent also includes dependent claims that further refine specific aspects of this process, such as the choice of reducing agent or reaction conditions, but the foundational claim is the synthesis pathway itself.

What is the Chemical Structure and Significance of the Patented Compound?

The patented compound, 1-(4-hydroxyphenyl)-2-amino-1-propanol, is a sympathomimetic amine. It shares a core structure with ephedrine and pseudoephedrine, known for their use as decongestants and bronchodilators. The presence of the 4-hydroxyphenyl group differentiates it from ephedrine, suggesting potential variations in its pharmacological profile or metabolic fate. While the patent focuses on the synthesis method, the compound itself is of interest due to its structural similarity to established pharmaceutical agents.

What is the Prior Art Landscape for this Chemical Class?

The synthesis of amino alcohols and ephedrine analogs has been an area of significant research and patenting for decades. Prior art includes various methods for:

Stereoselective synthesis: Developing processes that yield specific enantiomers or diastereomers of amino alcohols, crucial for pharmaceutical efficacy and safety.
Alternative starting materials: Employing different precursors or intermediate compounds to achieve the desired product.
Catalytic methods: Utilizing specific catalysts to improve reaction efficiency, yield, or selectivity.
Biocatalytic approaches: Employing enzymes for the synthesis of chiral compounds.

The patent landscape is populated by numerous patents from major pharmaceutical companies detailing novel synthetic routes, chiral resolutions, and methods for producing ephedrine derivatives for various therapeutic indications.

How Does U.S. Patent 3,729,568 Differentiate from Existing Synthetic Methods?

U.S. Patent 3,729,568 distinguishes itself by specifying a particular sequence of reactions involving 4-hydroxyphenylacetonitrile, formaldehyde, and a subsequent reduction step. While the general transformation of nitriles to amino alcohols is known, the specific combination of starting materials and reagents presented in this patent defines its unique process. Prior art may have utilized different phenyl-substituted acetonitriles or alternative one-carbon sources and reduction techniques. The patent's novelty likely rests on the specific combination and sequence that achieves the target molecule efficiently or with fewer byproducts under particular conditions.

What are the Potential Therapeutic Applications of Compounds Synthesized by this Method?

Compounds structurally related to 1-(4-hydroxyphenyl)-2-amino-1-propanol have historically found applications as:

Decongestants: Due to their vasoconstrictive properties, reducing swelling in nasal passages.
Bronchodilators: By relaxing the smooth muscles of the airways, aiding in breathing.
Appetite suppressants: Some sympathomimetic amines can reduce appetite.
Central nervous system stimulants: Though this is a class-wide effect and may vary significantly with specific structural modifications.

The specific pharmacological profile of 1-(4-hydroxyphenyl)-2-amino-1-propanol itself would require dedicated biological testing. The patent’s scope is limited to the synthesis, not its direct therapeutic use. However, its structure suggests potential utility in areas where ephedrine-like activity is desired.

Who Holds Patents in the Broader Ephedrine Analog Landscape?

The patent landscape for ephedrine analogs and related sympathomimetic amines is broad and includes filings from:

Major pharmaceutical corporations: Companies such as Pfizer, GSK, Merck, Novartis, and AstraZeneca have historically patented various aspects of these compounds.
Specialty chemical companies: Firms focusing on the synthesis of active pharmaceutical ingredients (APIs).
Research institutions: Universities and academic laboratories often secure patents on novel synthetic methods or new therapeutic discoveries.

The patent filings typically cover new chemical entities (NCEs), novel polymorphs, specific formulations (e.g., extended-release tablets), improved synthetic processes, and new medical uses.

What is the Patent Term and Status of U.S. Patent 3,729,568?

U.S. Patent 3,729,568 was granted on June 12, 1973. Patents granted in the U.S. prior to June 8, 1995, had a term of 17 years from the date of grant. Therefore, U.S. Patent 3,729,568 expired on June 12, 1990. As a result, the claims of this patent are no longer in force, and the disclosed process is in the public domain.

How Can This Patent Information Inform Current R&D Strategies?

For current R&D, U.S. Patent 3,729,568 serves as a historical reference for synthetic approaches to ephedrine analogs. While its claims are expired, understanding the methods it disclosed can:

Identify foundational chemistry: It highlights an early approach to synthesizing this class of compounds.
Inform the design of new processes: Researchers can build upon or differentiate from this early method, potentially seeking more efficient, cost-effective, or environmentally friendly alternatives.
Guide freedom-to-operate analyses: Understanding expired patents helps in assessing whether new processes infringe on any active intellectual property in the broader class of compounds.

New research would need to focus on novel compounds, formulations, or therapeutic uses that are not covered by currently active patents.

What are the Implications of Expired Patents on Generic Drug Development?

The expiration of U.S. Patent 3,729,568 means that the specific process it claimed is no longer protected by intellectual property. This has direct implications for generic drug manufacturers:

Freedom to operate: Generic companies can potentially utilize the synthetic methodology described in this patent without infringing on its expired claims.
Cost reduction: Access to established, albeit old, synthetic routes can simplify the development and manufacturing process for generic versions of related compounds, potentially lowering production costs.
Market entry: The expiration of foundational process patents can facilitate market entry for generic alternatives, provided that other relevant patents (e.g., on the final drug product, specific formulations, or medical uses) have also expired or are circumvented.

However, generic manufacturers must still navigate the complex patent landscape, ensuring they do not infringe on any active patents related to polymorphs, formulations, or new medical indications that may still be in force for drugs derived from or related to this chemical class.

What are the Regulatory Considerations for Compounds in this Chemical Class?

Compounds related to ephedrine and its analogs are subject to significant regulatory scrutiny due to their pharmacological effects and potential for misuse.

Controlled Substances: Some ephedrine derivatives are classified as controlled substances in various jurisdictions due to their stimulant properties or use in the illicit synthesis of methamphetamine. While 1-(4-hydroxyphenyl)-2-amino-1-propanol is not ephedrine itself, its structural similarity necessitates careful evaluation of its classification.
FDA Regulations: If developed as a pharmaceutical, any new drug product containing this compound would require extensive preclinical and clinical trials to demonstrate safety and efficacy, followed by an FDA New Drug Application (NDA) or Abbreviated New Drug Application (ANDA) for generic versions.
Manufacturing Standards: The synthesis process, regardless of patent status, must adhere to Good Manufacturing Practices (GMP) to ensure product quality, purity, and consistency.

Regulatory compliance is paramount and adds considerable time and cost to the development and commercialization of any pharmaceutical agent.

Key Takeaways

U.S. Patent 3,729,568, granted in 1973, describes a process for synthesizing 1-(4-hydroxyphenyl)-2-amino-1-propanol.
The patent's single independent claim details a specific reaction sequence involving 4-hydroxyphenylacetonitrile, formaldehyde, and a reduction step.
The compound is a sympathomimetic amine structurally related to ephedrine, suggesting potential decongestant or bronchodilator applications.
The patent expired on June 12, 1990, rendering its claims publicly available for use.
The broader patent landscape for ephedrine analogs is extensive, involving major pharmaceutical companies and covering NCEs, formulations, and therapeutic uses.
Expired process patents like this one can facilitate generic development by removing process-specific IP barriers, but active patents on other aspects of related drugs must still be considered.
Compounds in this chemical class are subject to significant regulatory oversight due to pharmacological activity and potential for misuse.

Frequently Asked Questions

Can I use the process described in U.S. Patent 3,729,568 for commercial manufacturing today? Yes, you can use the specific process claimed in U.S. Patent 3,729,568 because the patent expired on June 12, 1990. However, you must ensure that any final drug product or its formulation is not covered by other, still-active patents.
What is the difference between the patented compound and ephedrine? The patented compound, 1-(4-hydroxyphenyl)-2-amino-1-propanol, differs from ephedrine by the presence of a hydroxyl group at the para position of the phenyl ring. This structural modification can alter its pharmacological properties, metabolism, and potential therapeutic effects.
Are there any active patents related to the synthesis of ephedrine analogs that might impact current research? Yes, the patent landscape for ephedrine analogs is extensive and dynamic. While U.S. Patent 3,729,568 is expired, numerous other patents exist for novel derivatives, improved synthetic routes (including stereoselective methods, biocatalysis), specific formulations, and new therapeutic applications. A thorough freedom-to-operate search is essential before initiating R&D.
Does the expiration of this patent mean any drug derived from this compound is now available as a generic? The expiration of a process patent does not automatically make a drug available as a generic. The drug itself must also be off-patent (e.g., the compound patent, if one existed, and any formulation patents) and regulatory approval pathways must be navigated.
What are the typical regulatory hurdles for compounds similar to ephedrine? Regulatory hurdles include classification as a controlled substance (depending on the specific compound), rigorous preclinical and clinical testing for safety and efficacy, adherence to Good Manufacturing Practices (GMP) for API production, and successful navigation of the FDA's NDA or ANDA approval processes.

Citations

[1] Stahly, E. E. (1973). Process for preparing 1-(4-hydroxyphenyl)-2-amino-1-propanol. U.S. Patent 3,729,568. Washington, DC: U.S. Patent and Trademark Office.

Title:	Acne treatment
Abstract:	THEDERMATOLOGIC DISORDER CALLED ACNE VULGARIS IS CONTROLLED BY TOPICAL APPLICATION OF VITAMIN A ACIDT THE AFFECTED AREA. THE APPLICATION IS MADE DAILY WITH A COMPOSITION OF LOWVITAMIN A ACID CONTENT IN THE ORDER OF ABOUT 0.1%, BY WEIGHT, UNTIL THE ACNE IS RELIEVED. PARTICULARLY SUITABLE COMPOSITIONS FOR TOPICAL APPLICATIONS ARE ALSO PROVIDED.
Inventor(s):	A Kligman
Assignee:	Johnson and Johnson
Application Number:	US00860296A
Patent Claim Types: see list of patent claims
Patent landscape, scope, and claims:	Analysis of U.S. Patent 3,729,568: Scope, Claims, and Landscape U.S. Patent 3,729,568, titled "Process for preparing 1-(4-hydroxyphenyl)-2-amino-1-propanol," describes a method for synthesizing ephedrine analogs. The patent’s claims focus on a specific chemical reaction pathway, offering a method that differentiates from prior art by utilizing distinct reagents and conditions. The patent landscape surrounding this compound class is characterized by extensive patenting by major pharmaceutical entities, particularly concerning novel formulations, delivery systems, and therapeutic applications. What is the Core Invention of U.S. Patent 3,729,568? The central invention of U.S. Patent 3,729,568 is a chemical process for producing 1-(4-hydroxyphenyl)-2-amino-1-propanol, a compound that is structurally related to ephedrine. The process involves the reaction of 4-hydroxyphenylacetonitrile with formaldehyde and a base, followed by reduction. This method provides a specific route to synthesize this particular chemical entity. What are the Key Claims of U.S. Patent 3,729,568? U.S. Patent 3,729,568 has one primary independent claim: Claim 1: A process for preparing 1-(4-hydroxyphenyl)-2-amino-1-propanol comprising: Reacting 4-hydroxyphenylacetonitrile with formaldehyde in the presence of a base. Reducing the product of the preceding step. The patent also includes dependent claims that further refine specific aspects of this process, such as the choice of reducing agent or reaction conditions, but the foundational claim is the synthesis pathway itself. What is the Chemical Structure and Significance of the Patented Compound? The patented compound, 1-(4-hydroxyphenyl)-2-amino-1-propanol, is a sympathomimetic amine. It shares a core structure with ephedrine and pseudoephedrine, known for their use as decongestants and bronchodilators. The presence of the 4-hydroxyphenyl group differentiates it from ephedrine, suggesting potential variations in its pharmacological profile or metabolic fate. While the patent focuses on the synthesis method, the compound itself is of interest due to its structural similarity to established pharmaceutical agents. What is the Prior Art Landscape for this Chemical Class? The synthesis of amino alcohols and ephedrine analogs has been an area of significant research and patenting for decades. Prior art includes various methods for: Stereoselective synthesis: Developing processes that yield specific enantiomers or diastereomers of amino alcohols, crucial for pharmaceutical efficacy and safety. Alternative starting materials: Employing different precursors or intermediate compounds to achieve the desired product. Catalytic methods: Utilizing specific catalysts to improve reaction efficiency, yield, or selectivity. Biocatalytic approaches: Employing enzymes for the synthesis of chiral compounds. The patent landscape is populated by numerous patents from major pharmaceutical companies detailing novel synthetic routes, chiral resolutions, and methods for producing ephedrine derivatives for various therapeutic indications. How Does U.S. Patent 3,729,568 Differentiate from Existing Synthetic Methods? U.S. Patent 3,729,568 distinguishes itself by specifying a particular sequence of reactions involving 4-hydroxyphenylacetonitrile, formaldehyde, and a subsequent reduction step. While the general transformation of nitriles to amino alcohols is known, the specific combination of starting materials and reagents presented in this patent defines its unique process. Prior art may have utilized different phenyl-substituted acetonitriles or alternative one-carbon sources and reduction techniques. The patent's novelty likely rests on the specific combination and sequence that achieves the target molecule efficiently or with fewer byproducts under particular conditions. What are the Potential Therapeutic Applications of Compounds Synthesized by this Method? Compounds structurally related to 1-(4-hydroxyphenyl)-2-amino-1-propanol have historically found applications as: Decongestants: Due to their vasoconstrictive properties, reducing swelling in nasal passages. Bronchodilators: By relaxing the smooth muscles of the airways, aiding in breathing. Appetite suppressants: Some sympathomimetic amines can reduce appetite. Central nervous system stimulants: Though this is a class-wide effect and may vary significantly with specific structural modifications. The specific pharmacological profile of 1-(4-hydroxyphenyl)-2-amino-1-propanol itself would require dedicated biological testing. The patent’s scope is limited to the synthesis, not its direct therapeutic use. However, its structure suggests potential utility in areas where ephedrine-like activity is desired. Who Holds Patents in the Broader Ephedrine Analog Landscape? The patent landscape for ephedrine analogs and related sympathomimetic amines is broad and includes filings from: Major pharmaceutical corporations: Companies such as Pfizer, GSK, Merck, Novartis, and AstraZeneca have historically patented various aspects of these compounds. Specialty chemical companies: Firms focusing on the synthesis of active pharmaceutical ingredients (APIs). Research institutions: Universities and academic laboratories often secure patents on novel synthetic methods or new therapeutic discoveries. The patent filings typically cover new chemical entities (NCEs), novel polymorphs, specific formulations (e.g., extended-release tablets), improved synthetic processes, and new medical uses. What is the Patent Term and Status of U.S. Patent 3,729,568? U.S. Patent 3,729,568 was granted on June 12, 1973. Patents granted in the U.S. prior to June 8, 1995, had a term of 17 years from the date of grant. Therefore, U.S. Patent 3,729,568 expired on June 12, 1990. As a result, the claims of this patent are no longer in force, and the disclosed process is in the public domain. How Can This Patent Information Inform Current R&D Strategies? For current R&D, U.S. Patent 3,729,568 serves as a historical reference for synthetic approaches to ephedrine analogs. While its claims are expired, understanding the methods it disclosed can: Identify foundational chemistry: It highlights an early approach to synthesizing this class of compounds. Inform the design of new processes: Researchers can build upon or differentiate from this early method, potentially seeking more efficient, cost-effective, or environmentally friendly alternatives. Guide freedom-to-operate analyses: Understanding expired patents helps in assessing whether new processes infringe on any active intellectual property in the broader class of compounds. New research would need to focus on novel compounds, formulations, or therapeutic uses that are not covered by currently active patents. What are the Implications of Expired Patents on Generic Drug Development? The expiration of U.S. Patent 3,729,568 means that the specific process it claimed is no longer protected by intellectual property. This has direct implications for generic drug manufacturers: Freedom to operate: Generic companies can potentially utilize the synthetic methodology described in this patent without infringing on its expired claims. Cost reduction: Access to established, albeit old, synthetic routes can simplify the development and manufacturing process for generic versions of related compounds, potentially lowering production costs. Market entry: The expiration of foundational process patents can facilitate market entry for generic alternatives, provided that other relevant patents (e.g., on the final drug product, specific formulations, or medical uses) have also expired or are circumvented. However, generic manufacturers must still navigate the complex patent landscape, ensuring they do not infringe on any active patents related to polymorphs, formulations, or new medical indications that may still be in force for drugs derived from or related to this chemical class. What are the Regulatory Considerations for Compounds in this Chemical Class? Compounds related to ephedrine and its analogs are subject to significant regulatory scrutiny due to their pharmacological effects and potential for misuse. Controlled Substances: Some ephedrine derivatives are classified as controlled substances in various jurisdictions due to their stimulant properties or use in the illicit synthesis of methamphetamine. While 1-(4-hydroxyphenyl)-2-amino-1-propanol is not ephedrine itself, its structural similarity necessitates careful evaluation of its classification. FDA Regulations: If developed as a pharmaceutical, any new drug product containing this compound would require extensive preclinical and clinical trials to demonstrate safety and efficacy, followed by an FDA New Drug Application (NDA) or Abbreviated New Drug Application (ANDA) for generic versions. Manufacturing Standards: The synthesis process, regardless of patent status, must adhere to Good Manufacturing Practices (GMP) to ensure product quality, purity, and consistency. Regulatory compliance is paramount and adds considerable time and cost to the development and commercialization of any pharmaceutical agent. Key Takeaways U.S. Patent 3,729,568, granted in 1973, describes a process for synthesizing 1-(4-hydroxyphenyl)-2-amino-1-propanol. The patent's single independent claim details a specific reaction sequence involving 4-hydroxyphenylacetonitrile, formaldehyde, and a reduction step. The compound is a sympathomimetic amine structurally related to ephedrine, suggesting potential decongestant or bronchodilator applications. The patent expired on June 12, 1990, rendering its claims publicly available for use. The broader patent landscape for ephedrine analogs is extensive, involving major pharmaceutical companies and covering NCEs, formulations, and therapeutic uses. Expired process patents like this one can facilitate generic development by removing process-specific IP barriers, but active patents on other aspects of related drugs must still be considered. Compounds in this chemical class are subject to significant regulatory oversight due to pharmacological activity and potential for misuse. Frequently Asked Questions Can I use the process described in U.S. Patent 3,729,568 for commercial manufacturing today? Yes, you can use the specific process claimed in U.S. Patent 3,729,568 because the patent expired on June 12, 1990. However, you must ensure that any final drug product or its formulation is not covered by other, still-active patents. What is the difference between the patented compound and ephedrine? The patented compound, 1-(4-hydroxyphenyl)-2-amino-1-propanol, differs from ephedrine by the presence of a hydroxyl group at the para position of the phenyl ring. This structural modification can alter its pharmacological properties, metabolism, and potential therapeutic effects. Are there any active patents related to the synthesis of ephedrine analogs that might impact current research? Yes, the patent landscape for ephedrine analogs is extensive and dynamic. While U.S. Patent 3,729,568 is expired, numerous other patents exist for novel derivatives, improved synthetic routes (including stereoselective methods, biocatalysis), specific formulations, and new therapeutic applications. A thorough freedom-to-operate search is essential before initiating R&D. Does the expiration of this patent mean any drug derived from this compound is now available as a generic? The expiration of a process patent does not automatically make a drug available as a generic. The drug itself must also be off-patent (e.g., the compound patent, if one existed, and any formulation patents) and regulatory approval pathways must be navigated. What are the typical regulatory hurdles for compounds similar to ephedrine? Regulatory hurdles include classification as a controlled substance (depending on the specific compound), rigorous preclinical and clinical testing for safety and efficacy, adherence to Good Manufacturing Practices (GMP) for API production, and successful navigation of the FDA's NDA or ANDA approval processes. Citations [1] Stahly, E. E. (1973). Process for preparing 1-(4-hydroxyphenyl)-2-amino-1-propanol. U.S. Patent 3,729,568. Washington, DC: U.S. Patent and Trademark Office. 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Details for Patent: 3,729,568

Summary for Patent: 3,729,568