United States Patent 4,734,416: Scope, Claims, and US Patent Landscape
United States Patent 4,734,416 claims carbostyril-based small molecules with a piperazine side chain and defines broad structural genus claims, narrower enumerated examples, and multiple medical-use claim groupings covering “central nervous controlling effect” and antihistaminic effect, including pharmaceutical compositions and human treatment dosing routes. The claims also include a structural “double bond/specific substitution” proviso that meaningfully narrows some sub-genuses.
Because the claim text provided is unusually long and includes multiple overlapping claim families (carbostyril derivative general formula, a second formula family labeled as a “dihydroquinoline” scaffold, and method/composition claims that reference specific dependent claims), the most actionable interpretation is claim-scope segmentation: (i) core chemical genus, (ii) two side-chain location regimes, (iii) bond-order regime across the 3- and 4-positions, and (iv) target “use” claim packages that track specific sub-claims.
1) What is the claimed chemical core in US 4,734,416?
Core scaffold: carbostyril / dihydrocarbostyril derivatives with a substituted alkoxy-piperazine side chain
The independent chemical claim anchors are claim 1, supported by additional independent-like genus language in later claim sets (notably claims 42 and 62). Claim 1 recites a carbostyril derivative “represented by the formula” with variables controlling:
- R1: hydrogen; alkyl (C1-C6); alkenyl (C2-C4); alkynyl (C2-C4); or phenyl-alkyl with an alkylene (C1-C4)
- R2: hydrogen atom
- R3: hydrogen or alkyl (C1-C6)
- R4: hydrogen or alkyl (C1-C4)
- R5: phenyl ring substituted by 1 to 3 groups selected from halogen, alkyl (C1-C4), alkoxy (C1-C4)
- X: halogen
- n: 0, 1, or 2 (integer)
- Q: fixed at 2
- l and m: each 0 or integer 1 to 6 with constraint l + m ≤ 6
- Carbostyril 3,4 bond order: a carbon-carbon bond at the 3- and 4-positions in the carbostyril skeleton is either single or double
- Side-chain substituted position: the substituted position of the side chain is any one of 4-, 5-, 6-, 7-, or 8-positions
- Salt: acid addition salts are included
A binding proviso that narrows some sub-genuses
The claim includes a specific proviso:
- If side chain is substituted at the 4-position AND the 3- or 4-position carbon-carbon bond is a double bond, then R2 does not exist.
This is an internal exclusion that limits the overlap between:
- 4-position side-chain substitution, and
- double bond at 3,4.
Practical impact: designs that put the side chain at the 4-position and force 3,4 double bond are pushed outside claim scope because the proviso eliminates R2.
2) Where does the side chain sit, and how does that change the scope?
Side-chain location options in the core genus
Claim 1 permits the side chain substitution position to be 4, 5, 6, 7, or 8. Dependent claims then narrow to specific positions:
- Claim 2: side-chain at 5- or 7-position
- Claim 3: side-chain at 4-, 6-, or 8-position
Then, more specific:
- Claim 4: if claim 2 and side-chain is 5-position
- Claim 5: if claim 2 and side-chain is 7-position
- Claim 34 (another dependent narrowing in a later claim family): side-chain at 5-, 6-, 7-, or 8-positions (with additional bond-order constraints)
- Claims 45-48: side-chain at specific positions 5 or 7 or 4/6/8 depending on dependency
Enumerated examples cluster heavily at 5-, 6-, 7-, and 8-positions
The explicit compound examples (claims 6-20, 31, 70-73, 107-110, and many later selection clauses) show the pattern that the inventive embodiments emphasize 7-position and 5-position, with additional variants at 6 and 8, and at times specify “3,4-dihydrocarbostyril” vs carbostyril.
Examples that illustrate the location emphasis:
- Claim 6: “7-[3-(4-Phenylpiperazinyl)propoxy]-3,4-dihydrocarbostyril”
- Claims 10-12: “7-[3-(4-Phenylpiperazinyl)propoxy]…”, “1-Methyl-7-[3-(4-phenylpiperazinyl)propoxy]…”
- Claims 14-15: 5-[3-(4-Phenylpiperazinyl)propoxy]-… and 6-[3-(4-Phenylpiperazinyl)propoxy]-…
- Claim 17: “8-Bromo-5-[3-(4-phenylpiperazinyl)propoxy]-3,4-dihydrocarbostyril”
Business read-through: the claims are genus-wide, but the written descriptions and dependent claim narrowing in later prosecution-style trees indicate focus on piperazine-alkoxy substitution at the aromatic carbostyril ring positions, especially 5-7.
3) How does the 3,4 bond order limit claim coverage?
Single vs double bond is a global genus parameter
Claim 1: the carbon-carbon bond at the 3- and 4-positions “is a single or double bond.”
Dependent constraints are used to carve sub-genuses:
- Claim 25: explicitly sets the 3- and 4-positions bond as a single bond, and locks additional variables
- Claim 34: sets the 3- and 4-positions bond as a double bond
- Claim 110: “The compound of claim 95, wherein the carbon-carbon bond at the 3- and 4-positions … is a double bond.”
Proviso compounds interaction
The double bond constraint becomes more sensitive when combined with:
- side chain at 4-position, and
- the proviso requirement about R2 not existing.
Thus, bond-order and side-chain-position together create an exclusion zone for certain 4-position/3,4-double bond members.
4) What are the “pharmacological effect” claim packages and what do they require?
The patent uses disease-effect language to frame method and composition claims. Two main buckets appear:
(A) “Central nervous controlling effect” packages
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Claim 21: “A central nervous controlling agent” with compound (per claim 1) plus pharmaceutically acceptable carrier
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Claim 27: “A composition having a central nervous controlling effect comprising a compound as defined in claim 26”
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Claims 28-29: human treatment methods with dosing limits and route
- Claim 28: oral administration; dosage about 40 µg to 2 mg/kg/day
- Claim 29: intravenous administration; dosage about 40 µg to 2 mg/kg/day
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Claims 74-76: additional method instances tied to claim 26
- Claim 75: oral
- Claim 76: intravenous
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Claim 77: composition having central nervous controlling effect comprising compound as defined in claim 26
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Claim 78: method treating patient for either central nervous controlling effect or antihistaminic effect (depending on the claim-set cross-reference), with administration of compound per claim 26
(B) “Antihistaminic effect” packages
- Claim 40: composition combining antihistaminic and central nervous controlling effect; active ingredient defined by claim 34
- Claim 41: method producing central nervous controlling effect or antihistaminic effect via administering compound per claim 34
Later, claim 49 and 50 expand an antihistaminic composition and method family tied to claim 42:
- Claim 49: antihistaminic pharmaceutical composition with carrier
- Claim 50: method producing antihistaminic effect in mammal via administering composition with compound of the formula in claim 42
Claims 69, 71, 72 etc. create additional specific composition and method instances in that family:
- Claim 69: pharmaceutical composition usable as antihistaminic agent with active ingredient of claim 62
- Claims 77-81: combined effect packages that reuse the “central nervous controlling” and “antihistaminic” terms
Key scope outcome:
Even if the chemistry is broad, the medical-use claims often lock in specific dependent claim definitions (notably claim 26, 34, and 42/62 families). That creates a practical “claimability ladder” where not every genus compound is in every use claim, depending on whether it falls within the dependent-defined sub-genus.
5) What do the enumerated compound claims cover?
Representative enumerated “example” members (central nervous controlling effect focus)
Examples listed in the claim set show recurring piperazine substituents:
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Phenylpiperazinyl propoxy derivatives (7-position / 3,4-dihydrocarbostyril)
- Claim 6: 7-[3-(4-Phenylpiperazinyl)propoxy]-3,4-dihydrocarbostyril
- Claim 10: 7-[3-(4-Phenylpiperazinyl)propoxy]carbostyril
- Claim 18: 7-{3-[4-(2-Methoxyphenyl)piperazinyl]propoxy}-3,4-dihydrocarbostyril
- Claim 19: 7-{3-[4-(4-Methylphenyl)piperazinyl]propoxy}-3,4-dihydrocarbostyril
- Claim 16: 7-{3-[4-(2-Chlorophenyl)piperazinyl]propoxy}-3,4-dihydrocarbostyril
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Substituted phenylpiperazine variants
- Claim 8: 7-{3-[4-(3-Chlorophenyl)piperazinyl]propoxy}-3,4-dihydrocarbostyril
- Claim 9: 7-{3-[4-(2-Fluorophenyl)piperazinyl]propoxy}-3,4-dihydrocarbostyril
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Alkylated at the carbostyril nitrogen carbon position
- Claim 12: 1-Methyl-7-[3-(4-phenylpiperazinyl)propoxy]-3,4-dihydrocarbostyril
- Claim 20: 1-Benzyl-5-[3-(4-phenylpiperazinyl)propoxy]-3,4-dihydrocarbostyril
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Ether chain length variants
- Claim 13: 7-[4-(4-Phenylpiperazinyl)butoxy]-3,4-dihydrocarbostyril
Other enumerated members tied to the later “claim 62/42 family” scope
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Claim 70: 7-[3-(4-Benzylpiperazinyl)propoxy]-3,4-dihydrocarbostyril
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Claim 71: 7-[3-(4-Cyclohexylpiperazinyl)propoxy]-3,4-dihydrocarbostyril
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Claim 72: 5-[3-(4-Benzylpiperazinyl)propoxy]-3,4-dihydrocarbostyril
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Claim 73: 5-[3-(4-Benzoylpiperazinyl)propoxy]-3,4-dihydrocarbostyril
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Halogen and methyl substituted phenylpiperazines
- Claim 107: 7-{3-[4-(4-Chlorophenyl)piperazinyl]propoxy}-3,4-dihydrocarbostyril
- Claim 109: 5-{3-[4-(2-Fluorophenyl)piperazinyl]propoxy}-3,4-dihydrocarbostyril
These enumerations are important because later composition and method claims often key off dependent claim numbers (not off the absolute formula), so the examples provide direct “must-capture” candidates inside key sub-genuses.
6) How broad are the genus claims versus the dependent-use claims?
Genus breadth (chemistry)
Claim 1 is a wide structural genus:
- broad R-group substitution (alkyl, alkenyl, alkynyl, phenyl-alkyl),
- variable halogen and aromatic substitution counts on R5,
- variable side-chain position (4-8),
- variable bond order (single/double),
- includes acid addition salts.
Claim 42 and claim 62 are also broad, but they appear to have different variable constraints:
- Claim 42: includes R3 with hydroxy and specific protected/ester-like groups (alkanoyloxy and 3,4,5-trimethoxybenzoyloxy), and more permissive R5 substitution types, and side-chain positions 5-8.
- Claim 62: narrows R2 to “hydrogen atom, a C1-C4 alkyl group” and R5 to “cycloalkyl, substituted alkyl, alkanoyl, benzoyl” as well as phenyl substituted with 1-3 groups including halogen/alkyl/alkoxy.
Use-claim gating (medicine)
Medical-use claims gate coverage by referencing specific dependent definitions:
- Central nervous controlling effect claims: compositions/methods are tied to claim 26 (via claims 27-29 and 74-76 and 77-78).
- Combined effect claims: claim 40 and claim 41 tie to claim 34.
- Antihistaminic claims: claim 49 and claim 50 tie to claim 42; claim 69 ties to claim 62.
So the real “infringement calculus” is two-step:
1) Does your compound fall inside the cited dependent chemical sub-genus (claim 26, 34, 42, or 62)?
2) Does your use fall inside the cited method/composition effect language and dosing/route?
7) What does the later “dihydroquinoline” claim family add?
The claims also include a separate scaffold set labeled as:
- “A (4-substituted-piperazin-1-yl)alkoxy-2-oxo-1,2-dihydroquinoline” (claim 33 and later dependent claims 79-93 and selection sets 82-90 etc.).
This family changes at least:
- the core heterocycle naming (quinoline-like vs carbostyril),
- variable A is “valency bond or methylene radical,” with an explicit proviso:
- when A is methylene, R4 must be hydrogen.
- It includes n values 2-5 (vs the carbostyril claim family’s n with different ranges depending on section)
The landscape implication is that the patent portfolio is not only broad by functional group permutations, but also by scaffold family coverage that can sweep in closely related core heterocycles that still use a substituted piperazine-alkoxy chain.
8) Patent landscape in the US: what can be concluded from the record provided?
No patent landscape can be produced from the record provided because it lacks essential bibliographic identifiers and citation artifacts required for an accurate US landscape:
- filing and priority dates,
- assignee/applicant name,
- publication/application numbers,
- prosecution history or family members,
- the existence and status of continuations, divisionals, reissues, or related patents,
- the presence/absence of terminal disclaimers,
- and, crucially, any forward citations, backward citations, or subsequent patents that reference this grant.
Under the provided constraints, a complete and accurate US landscape cannot be generated.
Key Takeaways
- US 4,734,416 claims a broad carbostyril/3,4-dihydrocarbostyril chemical genus with a piperazine-alkoxy side chain, with structural coverage governed by R-group allowances, halogen/aromatic substitution constraints, variable 3,4 bond order, and side-chain position choices from 4 to 8.
- A targeted exclusion proviso narrows a specific corner: side-chain at the 4-position combined with a 3,4 double bond prevents R2 from existing.
- Medical-use claim coverage is segmented by dependent-claim gating: “central nervous controlling effect” depends heavily on claim 26; combined effect claims depend on claim 34; antihistaminic claims depend on claim 42 and claim 62.
- Enumerated examples concentrate on 5-, 6-, and 7-position substituted piperazine-alkoxy derivatives with phenyl and substituted phenylpiperazine moieties, plus linker-length variants (propoxy vs butoxy) and N-alkyl variations (methyl, benzyl).
- A US patent landscape cannot be responsibly constructed from the claim text alone because portfolio mapping requires bibliographic and citation data.
FAQs
1) What is the single biggest structural “scope limiter” in claim 1?
The proviso: if the side chain is at the 4-position and the 3- or 4-position bond is a double bond, then R2 does not exist.
2) Does claim 1 require the 3,4 bond to be double?
No. Claim 1 allows either single or double. Dependent claims later lock the bond type.
3) What side-chain positions are allowed in the core genus?
Claim 1 allows side-chain substitution at 4-, 5-, 6-, 7-, or 8-positions, with dependent claims narrowing to specific subsets.
4) Are dosing and administration routes claimed?
Yes. Human dosing is claimed at about 40 µg to 2 mg/kg/day, via oral (claim 28) and intravenous (claim 29) routes.
5) Can a compound be within the chemistry claim but not within a “central nervous controlling effect” use claim?
Yes. Central nervous controlling effect compositions and methods reference specific dependent claim definitions (not claim 1 directly in all instances), so use coverage depends on whether the compound fits the referenced sub-genus.
References
[1] United States Patent 4,734,416 (claim text provided by user).
