United States Patent 4,188,390: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 4,188,390, titled "Antihypertensive 4-amino-2-[4-(1,4-benzodioxan-2-carbonyl)piperazin-1-yl]-6,7-dimethoxyquinazoline," is a significant patent in the field of therapeutic agents, particularly for the treatment of hypertension. This analysis will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Field of the Invention
The patent pertains to novel derivatives of 4-amino-2-(piperazin-1-yl) or homopiperazin-1-yl)quinazoline, which are designed to regulate the cardiovascular system and specifically treat hypertension[1].
Description of the Invention
The invention involves compounds with the general formula:
[ \text{##STR2##} ]
where ( R ) represents 6,7-di(lower alkoxy) or 6,7,8-tri(lower alkoxy); ( n ) is 1 or 2; ( X ) represents --CHR₁-- or --CH₂CH₂--; and each of ( R_1 ) and ( R_0 ) represents hydrogen or lower alkyl. The most preferred compound is 4-amino-2-[4-(1,4-benzodioxan-2-carbonyl)piperazin-1-yl]-6,7-dimethoxyquinazoline[1].
Claims
The patent includes several key claims:
- Compound Claims: The patent claims novel compounds having the specified general formula, including the most preferred compound mentioned above.
- Method of Preparation: Claims include methods for preparing these compounds by reacting an appropriately substituted quinazoline with a piperazine or homopiperazine, typically under reflux in an inert organic solvent like n-butanol[1].
- Pharmaceutical Uses: Claims also cover the use of these compounds as hypotensive agents, specifically for treating hypertension.
Prior Art
The patent builds upon prior art that describes therapeutic properties of various quinazolines. For example, U.S. Pat. No. 3,511,836 and U.S. Pat. No. 3,669,968 describe similar compounds useful as hypotensive agents, but with different substituents[1].
Preparation and Purification
The compounds can be prepared through a reaction involving an appropriately substituted quinazoline and a piperazine or homopiperazine. The reaction is typically carried out under reflux in an inert organic solvent. The product is isolated and purified by conventional procedures, such as cooling the reaction mixture, collecting the crude solid product, washing it with cold solvent, and drying it[1].
Stereochemistry
The compounds may contain one or more asymmetric centers, resulting in pairs of enantiomers. These pairs or individual isomers can be separated by physical methods like fractional crystallization of suitable salts. The patent includes separated pairs as well as mixtures thereof, including racemic mixtures or separated d- and l-optically-active isomeric forms[1].
Pharmaceutical Significance
The compounds are valuable as regulators of the cardiovascular system, particularly in treating hypertension. The most preferred compound, 4-amino-2-[4-(1,4-benzodioxan-2-carbonyl)piperazin-1-yl]-6,7-dimethoxyquinazoline, is highlighted for its efficacy in this regard[1].
Patent Landscape
Related Patents
Other patents in the same domain, such as U.S. Pat. No. 3,511,836 and U.S. Pat. No. 3,669,968, describe similar quinazoline derivatives with different substituents. These patents collectively contribute to the broader landscape of therapeutic agents for cardiovascular diseases[1].
Global Patent System
The global patent system, facilitated by initiatives like the Global Dossier and Common Citation Document (CCD), ensures that patent applications and grants are harmonized across different jurisdictions. This harmonization is crucial for ensuring that inventions like those described in US4188390A are protected and recognized internationally[4].
Patent Data and Analytics
Datasets like the Patent Claims Research Dataset provided by the USPTO offer detailed information on claims from US patents and applications. These datasets can be used to analyze the scope and impact of patents like US4188390A within the broader patent landscape[3].
Legal and Regulatory Aspects
Patent Validity and Scope
The validity and scope of patent claims are subject to strict legal standards. For instance, reissue claims must comply with 35 U.S.C. § 251, ensuring that they are directed to the invention disclosed in the original patent. This requirement is crucial for maintaining the integrity of the patent system[5].
Public Access and Search Facilities
The USPTO provides various resources, including the Public Search Facility and Patent and Trademark Resource Centers (PTRCs), to facilitate public access to patent information. These resources are essential for researchers and inventors to navigate the patent landscape effectively[4].
Conclusion
United States Patent 4,188,390 represents a significant advancement in the development of therapeutic agents for hypertension. The patent's scope, claims, and preparation methods are well-defined, contributing to the broader landscape of cardiovascular treatments. Understanding the legal, regulatory, and global aspects of this patent is crucial for both researchers and practitioners in the field.
Key Takeaways
- Novel Derivatives: The patent introduces novel derivatives of quinazoline compounds for treating hypertension.
- Specific Compounds: The most preferred compound is 4-amino-2-[4-(1,4-benzodioxan-2-carbonyl)piperazin-1-yl]-6,7-dimethoxyquinazoline.
- Preparation Methods: Compounds are prepared through reactions involving quinazolines and piperazines or homopiperazines.
- Pharmaceutical Significance: These compounds are valuable as hypotensive agents.
- Legal and Regulatory Compliance: The patent adheres to strict legal standards regarding claim scope and validity.
FAQs
What is the primary use of the compounds described in US4188390A?
The primary use of the compounds described in US4188390A is as regulators of the cardiovascular system, specifically for treating hypertension.
How are the compounds prepared according to the patent?
The compounds are prepared by reacting an appropriately substituted quinazoline with a piperazine or homopiperazine, typically under reflux in an inert organic solvent like n-butanol.
What is the significance of the most preferred compound mentioned in the patent?
The most preferred compound, 4-amino-2-[4-(1,4-benzodioxan-2-carbonyl)piperazin-1-yl]-6,7-dimethoxyquinazoline, is highlighted for its efficacy in treating hypertension.
How do the compounds described in this patent fit into the broader patent landscape?
The compounds fit into a broader landscape of therapeutic agents for cardiovascular diseases, with related patents describing similar quinazoline derivatives with different substituents.
What legal standards must reissue claims comply with according to US patent law?
Reissue claims must comply with 35 U.S.C. § 251, ensuring that they are directed to the invention disclosed in the original patent.
Sources
- US4188390A - Antihypertensive 4-amino-2-[4-(1,4-benzodioxan-2-carbonyl)piperazin-1-yl]-6,7-dimethoxyquinazoline.
- U.S. Patent Small Claims Court - ACUS study on designing a small claims patent court.
- Patent Claims Research Dataset - USPTO dataset on patent claims.
- Search for patents - USPTO - Resources for searching and accessing patent information.
- In Re FLOAT'N'GRILL LLC - Court of Appeals for the Federal Circuit decision on reissue claims.
