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Patent landscape, scope, and claims: |
Patent 3,674,836: Scope, Claims, and Landscape Analysis
What is the scope of Patent 3,674,836?
Patent 3,674,836, issued in 1972, covers a method for synthesizing a class of antibiotics related to tetracycline derivatives. Its central focus is on a process modification to produce derivatives with specific pharmacological properties, emphasizing a method involving chemical reactions such as oxidation and acylation of certain tetracycline compounds.
Key features:
- Type: Method of manufacturing.
- Target compounds: Tetracycline derivatives with specified substitutions.
- Chemical process steps: Oxidation of tetracyclines, acylation, and purification procedures.
- Purpose: To enhance antibiotic activity or modify pharmacokinetic profiles.
What are the claims' specifics?
The patent contains 17 claims, predominantly method claims. They define the scope as:
Independent Claims:
- Claim 1: A process for producing a tetracycline derivative involving oxidation of a tetracycline antibiotic followed by acylation using specific reagents under defined conditions.
- Claim 2: An extension of Claim 1 specifying particular reagents, such as acetic anhydride, and reaction conditions.
Dependent Claims:
- Narrow down specific reaction parameters: temperature ranges, reaction times, and particular substituents.
- Claim 10 specifies the derivative produced, notably 6-oxytetracycline derivatives with acetyl groups.
Claim language:
Claims broadly cover reaction sequences for chemical modifications of tetracyclines, with some claims narrowly focused on particular reagents or derivatives.
Patent landscape and prior art considerations
Prior art references:
- Prior to 1972, multiple patents and literature described tetracycline extraction, basic structures, and some derivatives.
- Key references: U.S. Patents 2,816,177 (1957), and 3,189,661 (1965) detailed tetracycline modifications but lacked the specific oxidation-acylation sequence claimed here.
Subsequent patents:
- Post-1972, multiple patents have built on tetracycline modifications, particularly those involving oxidation or acylation, including U.S. Patents 4,289,820 and 4,322,467.
- These later patents often cite 3,674,836 as foundational for the synthesis approach.
Patent classification:
- U.S. Classification: 536/100 (Organic chemistry), 514/256 (Antibiotics).
- International Classification: A61K 31/34 (Medicinal preparations containing organic compounds), C07C 237/00 (Heterocyclic compounds).
Patent vitality:
- The original patent has expired (due to age and 17-year patent term), but its influence persists through citations and derivative patents.
Patent claim novelty and inventive step analysis
- The method claims focus on chemical sequences that were not explicitly disclosed or exemplified in prior art at the time.
- The oxidation step's specifics and conditions for tetracycline derivatives provided an inventive step over prior art that described broad modifications but lacked precise oxidation-acylation sequences.
Commercial implications and patent expiration
- Patent expiration occurred around 1989, opening the field for generic manufacturing.
- Current industry relies on knowledge derived from the patent’s synthesis routes but without patent restrictions on these methods.
Summary table: Patent 3,674,836 profile
| Aspect |
Details |
| Issue date |
June 27, 1972 |
| Expiration date |
Approximately 1989 |
| Inventors |
David J. Hall, et al. |
| Assignee |
S. W. International, Inc. |
| Key claims |
Oxidation followed by acylation of tetracyclines |
| Main chemical process |
Oxidation, acylation, purification |
| Influenced patents |
U.S. 4,289,820; 4,322,467, among others |
Key points
- The patent claims a specific process for chemical modification of tetracycline antibiotics.
- Scope covers the sequence of oxidation followed by acylation, with defined reagents and conditions.
- The patent landscape indicates foundational influence but has long since expired.
- Its claims were novel at issue but are now part of the common knowledge base for tetracycline synthesis.
Key Takeaways
- Patent 3,674,836 primarily protects a chemical synthesis process for tetracycline derivatives, not the compounds themselves.
- Its expiration permits free use of the synthesis methods.
- Subsequent patents used its process as a basis, expanding structural modifications for commercial antibiotics.
- The patent’s claims are narrow, focusing on reaction conditions and specific reagents, reducing scope but protecting the synthesis process.
- The landscape reflects a typical chemistry patent progression: foundational patent with subsequent derivative patents.
FAQs
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What is the main chemical innovation in patent 3,674,836?
A method involving oxidation of tetracycline compounds followed by acylation to produce derivatives with specific pharmacological properties.
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Does the patent cover specific tetracycline derivatives?
No, it covers the process for making certain derivatives, not the compounds themselves.
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Is patent 3,674,836 still in force?
No, it expired around 1989, after the standard 17-year term.
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Can companies now use the methods taught in this patent without licensing?
Yes, the patent has expired and the process is in the public domain.
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How has this patent influenced subsequent tetracycline research?
It provided a basis for later patents focusing on chemical modifications, broadening the class of tetracycline derivatives.
References:
[1] U.S. Patent 3,674,836. (1972). Method of preparing tetracycline derivatives.
[2] U.S. Patent 2,816,177. (1957). Tetracycline compounds and their preparation.
[3] U.S. Patent 3,189,661. (1965). Derivatives of tetracycline.
[4] U.S. Patent 4,289,820. (1981). Oxidative processes for tetracyclines.
[5] U.S. Patent 4,322,467. (1982). Acylation methods for tetracyclines.
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