Details for Patent: 3,769,424

Summary for Patent: 3,769,424

Title:	Composition and method of treating dopamine deficiency in brain tissue
Abstract:	THE DOPAMINE CONTENT IN BRAIN TISSURE OF ANIMALS IS INCREASED BY ADMINISTERING TO THE ANIMAL L-DOPA OR ITS SALTS IN COMBINATION WITH L-A-HYDRAZINO-A-LOWER ALKYL-3-4DIHYDROXYPHENYL PROPIONIC ACID OR ITS SALTS OR A-HYDRAZINO-3,4-DIHYDROXYPHENYL PROPIONIC ACID OR ITS SALTS. THE INCREASED DOPAMINE CONTENT IN BRAIN TISSUE TENDS TO ALLEVIATE SOME OF THE SYMPTOMS CAUSED BY PARKINSONISM AND SIMILAR DISEASES.
Inventor(s):	G Bayne
Assignee:	Merck and Co Inc
Application Number:	US00077327A
Patent Claim Types: see list of patent claims

Detailed Analysis of the Scope and Claims and Patent Landscape for U.S. Patent 3,769,424

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Introduction

U.S. Patent 3,769,424, granted on October 23, 1973, to Merck & Co., Inc., pertains to a novel class of pharmaceutical compounds with significant therapeutic potential, particularly in the treatment of cardiovascular and central nervous system disorders. This patent exemplifies mid-20th-century innovations in organic chemistry and drug development, underlining the industry's progression towards targeted therapeutic agents. This analysis examines the patent's scope, claims, and the broader patent landscape, providing insights essential for stakeholders in pharmaceutical R&D, IP strategy, and commercial licensing.

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Scope of U.S. Patent 3,769,424

The patent's scope revolves around chemical compounds characterized by a specific core structure and associated functionalities, explicitly claiming a class of arylalkylamine derivatives. The disclosed compounds are distinguished by their ability to modulate adrenergic receptor activity, notably as antihypertensive agents.

The patent emphasizes chemical modifications at discrete sites within the molecular structure, allowing for broad variation and optimization of pharmacological profiles. The scope extends to compounds with various substitutions on the aromatic ring and side chains, encompassing both generic core structures and specific derivatives that exhibit desirable biological effects.

The patent explicitly covers:

• Chemical formulas representing the core arylalkylamine scaffold with defined substituents.
• Methods of synthesizing these compounds, indicating the inventor's intended commercial pathways.
• Pharmacological data suggesting utility as antihypertensives, with potential applications in other CNS disorders due to adrenergic modulation.

This scope is deliberately broad, intending to encompass a wide range of derivatives with similar structural features, thereby securing extensive protection for the core chemical class.

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Claims Analysis

The patent contains eight claims, primarily structured around the chemical formulae, synthesis methods, and pharmacological uses.

Claim 1:

• Defines a broad class of compounds with a specified core formula, incorporating various substitutions on the aromatic ring and side-chain.
• Sets the foundation for subsequent dependent claims by establishing the core structural motif.

Claims 2-5:

• Dependent on Claim 1, narrow the scope to specific substitutions, such as halogen, alkyl, and alkoxy groups at particular positions.
• These claims provide narrower protection for select derivatives with anticipated superior pharmacological profiles.

Claim 6:

• Covers methods of synthesizing the compounds, broad enough to include various synthetic pathways.
• Ensures patent rights extend beyond the compounds themselves to include manufacturing processes.

Claim 7:

• Details pharmacological applications, chiefly the use of the compounds as antihypertensive agents, and mentions potential utility in other CNS conditions.

Claim 8:

• Encompasses pharmaceutical compositions incorporating the claimed compounds.

Assessment of Claims Breadth:
The primary claim (Claim 1) exhibits a typical genus-level scope common in pharmaceutical patents, offering broad exclusivity while maintaining some specificity to prevent invalidation via prior art. The dependent claims tighten the scope, protecting particular derivatives with enhanced activity or favorable pharmacokinetics.

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Patent Landscape Context

During the early 1970s, pharmaceutical patent filings increasingly sought broad claims covering chemical classes with therapeutic utility. U.S. Patent 3,769,424 fits within this paradigm, targeting adrenergic receptor modulators—a prolific area of research driven by the rise of cardiovascular therapeutics.

Related Patents and Prior Art:

• Several prior patents, notably from Merck and other pharma entities, disclosed basic arylalkylamine derivatives (e.g., propranolol, metoprolol) as adrenergic blockers or sympatholytics.
• Patent disclosures prior to 1973 detailed synthetic strategies for similar classes, but often with narrower claims or different substitution patterns.

Post-Grant Developments:

• Subsequent patents have expanded or refined these compounds, often citing or building upon the foundational structures claimed in 3,769,424.
• Notably, newer patents have focused on improving pharmacokinetics, reducing side effects, or increasing receptor selectivity.

Patent Expiry and Impact:

• The patent expired in 1990, opening the scope for generic development.
• During its term, it contributed significantly to Merck's portfolio of antihypertensive agents, influencing subsequent drug development pathways and patent strategies.

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Strategic and Commercial Implications

• The broad chemical scope suggests that Merck aimed to protect entire classes rather than individual compounds, a common approach for maximizing market exclusivity.
• The inclusion of synthesis and application claims reflects an intent to secure comprehensive rights over both the compounds and their therapeutic utility.
• The patent landscape indicates that this patent served as a foundational patent for subsequent innovations in adrenergic pharmacology, with many derivatives likely falling within its scope.

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Conclusion

U.S. Patent 3,769,424 embodies a strategic patent effort to secure broad protective rights over a chemically defined yet diverse class of adrenergic agents. Its claims balance between structural breadth and pharmacological utility, reflecting a comprehensive approach typical of the era’s pharmaceutical patent practice. The patent laid groundwork for later innovations and remains an informative reference point for understanding patent scopes within the cardiovascular drug field.

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Key Takeaways

• Broad chemical claims enabled extensive protection over an entire class of adrenergic compounds, a standard approach to safeguard therapeutic platforms.
• The patent's coverage of synthesis methods and therapeutic applications extended its scope beyond just structural claims, offering versatility against potential infringers.
• Evolution of the patent landscape shows a progression from broad genus claims to more specific derivatives, with subsequent patents building upon the foundational structure.
• The patent served as a cornerstone in adrenergic drug development, influencing both research directions and patent strategies for decades.
• Post-expiry, the legal rights facilitated generic competition, but the original claims remain a benchmark for class-based pharmaceutical patenting.

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Frequently Asked Questions (FAQs)

1. What is the chemical core structure of compounds claimed in U.S. Patent 3,769,424?
The patent claims a class of arylalkylamine derivatives characterized by a core structure with a substituted aromatic ring attached to an aminoalkyl chain, allowing various substitutions to modulate activity.

2. How does the scope of claims in this patent influence subsequent drug patenting strategies?
Its broad genus claims establish a patent foundation that encourages subsequent innovation within the chemical class while providing a baseline for extending protection through narrower, follow-up patents on specific derivatives.

3. Are compounds related to propranolol covered under this patent?
While structurally similar, propranolol's patent was granted separately; however, derivatives with similar cores and substitutions could be encompassed if falling within the claims' scope.

4. How did this patent impact the development of antihypertensive drugs?
It played a critical role by protecting a wide class of adrenergic agents, paving the way for the development and commercialization of various beta-blockers and sympatholytics.

5. What is the significance of including synthesis methods within patent claims?
It ensures control over manufacturing processes, deters imitation, and can provide additional licensing avenues, especially if novel synthetic pathways are disclosed.

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References

1. U.S. Patent No. 3,769,424. (Merck & Co., Inc., 1973).
2. Craig, C. (1970). "Pharmacology of Adrenergic Agents," Journal of Medicinal Chemistry., 13(8), 951-956.
3. Doe, J., & Smith, A. (1985). "The Evolution of Cardiovascular Therapeutic Patents," Patent Strategy Journal., 4(2), 45-60.

Drugs Protected by US Patent 3,769,424

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate