Scope, Claims, and U.S. Patent Landscape for US Drug Patent 11,492,353
Summary: US Patent 11,492,353 claims a class of compounds defined by Formula III, with key substituent constraints on R2, R3, R6, R7, R9, Ra, R11, and R. The claim set is structurally nested: independent Claim 1 sets the general chemical scope; dependent claims narrow to specific R2/R3 hydroxyl vs ester patterns, and specific R7 acyl groups including branched α-amino acid-derived acyls such as —(C═O)—CH(CH3)2 and —(C═O)—CH(NH2)CH(CH3)2. The overall landscape risk for competitors is tied to whether earlier patents disclose overlapping Formula III structures (or specific embodiments) and whether later prosecution history or continuation filings add further permutations of the same scaffold.
What does Claim 1 actually cover?
Core structural definition: A compound having the structure of Formula III or a pharmaceutically acceptable salt, with these fixed and variable elements:
Fixed elements (must match)
- R6 = CN
- R9 = H
- R7 is defined by one of two equivalent patterns:
- either R7 = (C═O)R11
- or R7 = R8 is NH2 (as written in the claim, this is coupled to the same overarching R7/R11 framework)
- Ra occurrences are each independently H or (C═O)R11
- R11 occurrences are each independently:
- H or
- (C1-C8)alkyl, optionally substituted by NH2
- R occurrences are each independently:
Variable “high-impact” elements
- R2 and R3 are each ORa
- Ra is either H or (C═O)R11
- So, at R2 and R3 positions:
- ORa can become OH when Ra = H
- or can become an ester when Ra = (C═O)R11
- Net effect:
- R2/R3 can be OH (Claim 4)
- or can be esterified with an acyl group that itself includes R11 = H or optionally NH2-substituted alkyl
Independent claim scope in plain structural terms
- A single scaffold (Formula III) with:
- a cyano group at R6
- a hydrogen at R9
- substituents at two positions (R2 and R3) that can be:
- hydroxyl
- or O-acyl using a carbonyl linked to R11
- an acyl/amide-like substituent at R7 controlled by R11 (depending on how R7 is written in the claim)
Key included functional motif
- The dependent claims explicitly lock onto R7 as:
- —(C═O)—(C1-C8)alkyl
- or more specifically:
- —(C═O)—CH(CH3)2 (isobutyryl-like acyl)
- —(C═O)—CH(NH2)CH(CH3)2 (α-amino, branched acyl motif)
How dependent claims narrow the chemical space
The dependent claims are mostly “combinatorial narrowing” around three axes:
1) whether R2/R3 are OH vs O-acyl
2) the allowed identities for the alkyl/acyl side chains
3) selection of R7 as either a simple branched acyl or an aminated branched acyl
R2/R3 branch point: OH vs O(C═O)(alkyl)
- Claim 4: “wherein R2 and R3 are each OH.”
- Claim 8: “wherein R2 and R3 are each —O(C═O)(C1-C8)alkyl … optionally substituted with NH2.”
- Claim 18: “wherein R2 is OH and R3 is —O(C═O)(C1-C8)alkyl …”
- Claim 25: “wherein R3 is OH and R2 is —O(C═O)(C1-C8)alkyl …”
- Claim 32: “wherein R2 and R3 are each —O(C═O)(C1-C8)alkyl.”
This produces at least four “structural families” already claimed:
- (i) di-hydroxy (R2 = OH, R3 = OH)
- (ii) mixed OH/ester (R2 OH, R3 ester)
- (iii) mixed ester/OH (R2 ester, R3 OH)
- (iv) di-ester (R2 and R3 both esterified)
The alkyl identity set (used repeatedly)
Multiple dependent claims restrict the (C1-C8)alkyl (optionally NH2-substituted) to a common list:
Allowed C1-C8 alkyls (set reused across claims):
- methyl
- ethyl
- n-propyl
- i-propyl
- 1-butyl
- 2-methyl-1-propyl
- 2-butyl
- 2-methyl-2-propyl
- 2-pentyl
- 3-pentyl
- 2-methyl-2-butyl
- 3-methyl-2-butyl
- 3-methyl-1-butyl
- 2-methyl-1-butyl
Where claims state “optionally substituted by NH2,” the same scaffold permits either unsubstituted alkyl or aminated versions at the alkyl side chain position.
R7 branch point: which acyl groups are explicitly covered
The dependent claims include specific embodiments:
- Claim 5: R7 is —(C═O)—(C1-C8)alkyl, with the same list of alkyl choices, each optionally substituted by NH2.
- Claim 6: R7 is —(C═O)—CH(CH3)2
- Claim 7: R7 is —(C═O)—CH(NH2)CH(CH3)2
- Claim 13: R7 is —(C═O)—(C1-C8)alkyl, same allowed alkyl list with optional NH2
- Claims 15 and 16: R7 is specifically:
- —(C═O)—CH(CH3)2
- —(C═O)—CH(NH2)CH(CH3)2
- Claims 23 and 24 and Claims 30 and 31 repeat the same two explicit R7 embodiments within different R2/R3 settings.
- Claim 34: R7 is —(C═O)—(C1-C8)alkyl
- Claim 36: R7 is —(C═O)—(C1-C8)alkyl with a further restriction to the same explicit alkyl list
Practical read-through: independent Claim 1 already includes these R7 forms indirectly through R11 options, while dependents make them positively asserted and thus easier to enforce against accused products that match those specific side-chain identities.
Claims 3, 5, 8, 9, 10, 12: R substitutions at Ra positions
The dependents also specify embodiments where R (a different placeholder than R2/R3) is selected from the same C1-C8 alkyl list. These are primarily:
- Claim 3: R is selected from the enumerated alkyl list.
- Claims 5/8/9/10/12/14/17/19/20/21 etc.: these mostly restrict the alkyl identity at acyl carbonyl substituents attached through ORa or at R7.
The key enforcement implication is that the claim set uses the same “alkyl enumerations” repeatedly, so an accused compound that matches one of the enumerated branched alkyl choices is more likely to fall squarely within a dependent claim even if outside the broadest interpretation of Claim 1.
Claim matrix: what is uniquely “strong” for enforcement?
Below is a compact matrix of the most specific, narrow, and therefore highest-value claim hooks.
| Claim subset |
Where it constrains |
Specific locked motifs |
| Claims 4, 18, 25, 8, 32 |
R2/R3 oxygenation state |
OH/O-ester patterns (di-hydroxy, mixed, di-ester) |
| Claims 6 and 7 (also mirrored by 15-16, 23-24, 30-31) |
R7 acyl group |
—(C═O)—CH(CH3)2 and —(C═O)—CH(NH2)CH(CH3)2 |
| Claims 5, 9, 10, 13, 14, 17, 19, 22, 26, 28, 29, 35, 37 |
side-chain identity |
restricts (C1-C8)alkyl to a defined set; optionally NH2-substituted |
| Claims 10-12 and 17 |
dual ester identity constraints |
ties R2 and R3 to specific acyl variants and positions |
Net: the most enforceable embodiments are those that match:
- R6 = CN and R9 = H (fixed)
- R2/R3 state (OH vs O-acyl)
- and R7 exact acyl motif (especially the two explicit branched acyl forms).
Scope vs literal risk: how competitors can try to design around
Based on the claim language alone, design-around options typically target one or more fixed elements:
High-friction features to avoid
- R6 = CN: removing or replacing the cyano likely falls outside the literal scope.
- R9 = H: altering that position risks non-infringement.
- R2/R3 architecture: moving away from ORa (hydroxyl or acyl ester via Ra carbonyl to R11) can avoid.
Conditional “soft spots” (but still constrained)
- R2/R3 ester acyl identity: even where acyl is allowed, claims constrain R11 = H or (C1-C8)alkyl optionally NH2-substituted, using the enumerated set in many dependents.
- R7 acyl group: explicit dependents cover two acyls; if an accused compound uses a different acyl, it may avoid those dependents while still potentially falling under Claim 1 if its R11 composition still fits the broader definition.
“Most likely overlap” for competitors
- Any product that matches the two explicit R7 acyls:
- —(C═O)—CH(CH3)2
- —(C═O)—CH(NH2)CH(CH3)2
- and uses R2/R3 as OH or as O-acyl with alkyls from the enumerated list
- presents a higher literal infringement probability across multiple dependent claims.
U.S. patent landscape: what can be said from the claim text provided
No bibliographic identifiers, assignee, publication numbers, priority dates, prosecution history, or family members were provided. Without those, a complete landscape with specific citing patents, claim chart overlaps, or family map cannot be generated from the information on hand.
Given that limitation, the actionable landscape read from the claim set is structural, not bibliographic:
What later entrants must clear (freedom-to-operate lens)
A competitor looking to avoid overlap with US 11,492,353 must typically demonstrate at least one of the following:
- a different core scaffold than Formula III
- replacement or absence of the R6 cyano element
- change at R9
- change in the R2/R3 oxygenation/ester architecture such that it is no longer ORa with Ra = H or (C═O)R11
- use of R7 substituents whose R11 mapping does not satisfy the claim’s R11 definition and the dependent enumerations
What is likely “busy” in the landscape
This claim family’s structural features suggest it sits in a crowded neighborhood of:
- CN-bearing heteroaromatic or substituted cores (if Formula III is heterocyclic)
- substituted acyl/ester variants with branched C1-C8 alkyls
- amino-substituted alkyl side chains including α-amino branched acyl motifs (e.g., CH(NH2)CH(CH3)2)
In practice, that means earlier art (by others) often includes partial overlaps:
- the same scaffold with different acyl groups
- the same acyl groups on a closely related core with modified R6/R9 or oxygenation patterns
But those are general portfolio observations; no specific patent citations can be asserted without the missing bibliographic record.
Key Takeaways
- Claim 1 defines a Formula III compound class with fixed R6 = CN and R9 = H, plus variable R2/R3 = ORa where Ra = H or (C═O)R11; R11 is H or a (C1-C8)alkyl optionally NH2-substituted.
- Dependent claims carve out enforcement-critical subspaces around:
- R2/R3 = OH vs O-acyl combinations (di-hydroxy, mixed, di-ester)
- R7 acyl identity, including explicit coverage of —(C═O)—CH(CH3)2 and —(C═O)—CH(NH2)CH(CH3)2
- a repeated enumerated list of branched (C1-C8)alkyl groups, optionally NH2-substituted.
- Without the patent’s bibliographic dossier (publication, assignee, priority, family), the specific citation-based landscape (which patents overlap, block, or are design-around targets) cannot be produced from the claim text alone.
- For freedom-to-operate, the most direct literal-risk levers are the cyano (R6), the R9 hydrogen, the ORa architecture at R2/R3, and the R7 acyl motif.
FAQs
1) Is the cyano group at R6 mandatory for infringement?
Yes. Claim 1 states R6 is CN, and all dependent claims build on Claim 1.
2) Can R2 and R3 be hydroxyls?
Yes. Claim 4 covers R2 and R3 each OH, while other dependents cover mixed and di-ester forms.
3) Which R7 acyl groups are explicitly called out with specific structures?
—(C═O)—CH(CH3)2 and —(C═O)—CH(NH2)CH(CH3)2 are explicitly recited (e.g., Claims 6-7, also mirrored in later dependents).
4) Does the claim cover aminated alkyl substituents?
Yes. R11 and multiple dependents allow (C1-C8)alkyl optionally substituted by NH2, and R7 includes an explicitly NH2-containing branched acyl in the enumerated embodiment.
5) Does the claim require both R2 and R3 to be esters to fall in scope?
No. Scope includes both OH, both esters, and mixed OH/ester patterns across dependent claims.
References
- Provided claim text for U.S. Drug Patent 11,492,353 (user-supplied claims).
