United States Patent 4,943,569 (β-lactam) Scope, Claim Construction, and U.S. Patent Landscape

Executive summary. U.S. Patent 4,943,569 claims a structurally defined β-lactam scaffold with variable substituents at multiple positions: (i) a 6-(1-hydroxyethyl) motif, (ii) a sidechain “Y” defined by a substituted heteroatom-linked cyclic amino/amide/alkylamino family, (iii) a variable “X” methylene (unsubstituted vs substituted), and (iv) stereochemical variants (5R/5S and additional stereocenters) down to enumerated active species. Claim coverage runs from Markush-type genus claims (claims 1–2) through narrow species examples (claims 10–22) and then to downstream life-cycle claims (composition and antimicrobial method-of-use: claims 23–24; stereochemical “compound of” dependent forms: claims 25–34; further β-lactam formula claims: claims 35–37; additional stereochemical enumerations: claims 38–39). The most commercially relevant risk for challengers is that the patent’s broadest independent claims (1–2) are drafted to read on any β-lactam within the specified scaffold and sidechain families, including protected-hydroxy/amine/carboxyl variants, while the remaining claims tighten coverage to specific marketed-type stereoisomers and sidechains.

What is U.S. Patent 4,943,569 claiming, and what is the β-lactam scaffold coverage?

Short answer. The patent claims β-lactam compounds defined by a constrained bicyclic β-lactam core (1-azabicyclo[3,2,0]hept-2-ene/7-one-2-carboxylic acid framework) with substitution patterns at R1 (1-hydroxyethyl), R2 (amine protection or hydrogen), R3 (carboxyl protection or hydrogen) and a substituent family Y that is constrained to small cyclic amino structures formed from R5/R6 definitions (including N-linked and heteroatom-linked ring closures).

Core structural elements repeatedly enforced across claims

β-lactam ring + azabicyclic system: all species and formula claims center on 1-azabicyclo[3,2,0]hept-2-ene-7-one (claims 10–14 etc.) or the corresponding hept-3-ene variant (claim 12).
Carboxylic acid function: expressed as -1-azabicyclo[3,2,0]hept-…-one-2-carboxylic acid in the enumerated species (claims 10–22).
6-(1-hydroxyethyl) motif:
- In the explicit species claims (10–14 etc.) and genus claims through the R1 parameter.
- R1 explicitly includes free 1-hydroxyethyl and protected hydroxy forms (genus claim text: “1-hydroxyethyl group or 1-hydroxyethyl group in which the hydroxy group is protected”).
Sidechain “Y” defined by formula (2) with R5/R6 parameters:
- R5 and R6 can be H, short alkyl (C1–C4), alkenyl (C3–C4), aralkyl (C1–C3 alkyl portion), substituted alkyl (C1–C4) bearing hydroxyl, di(C1–C3)alkylamino, or carbamoyl, or joined to form a ring closure:
  - via carbon chain to form a 4- to 7-membered cyclic amino group, or
  - via oxygen/sulfur/(C1–C3)-alkyl-substituted nitrogen to form a cyclic amino group with specified ring sizes.

How “X” shapes claim boundaries

In claim 1, X is an unsubstituted methylene group.
In claim 2, X is substituted methylene of formula (1) where R4 = alkyl having 1–3 carbons.
This yields a clean partition:
- claim 1 targets an unsubstituted X position.
- claim 2 extends to an alkyl-substituted methylene at the X position.

What do the “protected group” allowances do?

R1/R2/R3 include protected hydroxy, amino, and carboxyl variants.
That typically expands coverage to prodrug-like intermediates or protected derivatives that can be deprotected to the active acid/amine/alcohol, while still tethered to the same β-lactam scaffold and sidechain Y definition.

How broad are claims 1 and 2 (genus coverage) compared with the species claims 10–22?

Short answer. Claims 1–2 are Markush genera that can capture many members defined by substituent options and ring-forming heteroatom linkages. Claims 10–22 then lock into specific stereospecific “Y” sidechains and (5R/5S) variants that map to particular cyclic amino/amide substituents.

Genus claims (independent) in functional scope

Claim 1 (high-level):

β-lactam scaffold with:
- R1: 1-hydroxyethyl (free or protected),
- R2: hydrogen or protected amino,
- R3: hydrogen or protected carboxyl,
- X: unsubstituted methylene,
- Y: cyclic amino family defined by R5/R6 rules (formula (2)),
- and pharmaceutically acceptable salts.

Claim 2 (high-level):

same scaffold family but:
- X: substituted methylene with R4 = alkyl (C1–C3),
- Y: same R5/R6 cyclic amino family as claim 1,
- includes salts.

Species claims (enumerated drug-like compounds)

Claims 10–14 list (5R)-configured compounds with specific Y sidechains:

Claim 10: (5R) with (1-Pyrrolidino)carbonyl substitution.
Claim 11: (5R) with (1-Azetidino)carbonyl substitution.
Claim 12: (5R) with (2-Hydroxyethyl)methylamino carbonyl substitution; uses hept-3-ene variant in formula.
Claim 13: (5R) with (1-Morpholinocarbonyl) substitution.
Claim 14: (5R) with (1-N-Methylpiperazinocarbonyl) substitution.

Claims 15–22 list (5S) analogs with closely related sidechains:

Claim 15: (5S) Carbamoyl pyrrolidinylthio sidechain.
Claim 16: (5S) Dimethylaminocarbonyl.
Claim 17: (5S) (1-pyrrolidino)carbonyl.
Claim 18: (5S) (1-Azatidino)carbonyl.
Claim 19: (5S) (2-Hydroxyethyl)methylaminocarbonyl.
Claim 20: (5S) (1-Morpholinocarbonyl).
Claim 21: (5S) (1-N-Methylpiperazinocarbonyl).
Claim 22: (5S) Carbamoyl pyrrolidinylthio.

Practical claim-scoping takeaways

If a competitor’s compound differs only by:
- stereochemistry (5R vs 5S) and/or
- the exact cyclic amino ring size (within 4–7 rules) and/or
- choosing oxygen/sulfur/nitrogen heteroatom linked ring closures, it may still land inside claim 1 or 2 if the X position and scaffold match.
If it changes:
- the X methylene substitution state (unsubstituted vs R4 alkyl C1–C3), then claim 1 vs claim 2 becomes the immediate gating issue.
If it changes:
- the sidechain Y family to structures outside the defined R5/R6 ring/functional groups, then both genera are avoided.

Which exact compounds are explicitly covered (claims 10–22), and how do stereochemistry-dependent claims expand protection?

Short answer. The patent explicitly names multiple (5R) and (5S) stereoisomer species with particular Y-sidechain carbonyl carriers (pyrrolidino, azetidino/azatidino, morpholino, N-methylpiperazino, carbamoyl, dimethylamino carbonyl, and hydroxyethyl methylamino carbonyl). It then adds further stereochemical layering via dependent claims 25–34 and 38–39 for multi-stereocenter variants.

Explicit stereochemical species map

Claim	Base configuration	“Y” / sidechain type (as stated)	X position implication
10	(5R)	(1-Pyrrolidino)carbonyl	covered under claim 1/2 scaffold depending on X genus match
11	(5R)	(1-Azetidino)carbonyl	same
12	(5R)	(2-Hydroxyethyl)methylaminocarbonyl	same
13	(5R)	(1-Morpholinocarbonyl)	same
14	(5R)	(1-N-Methylpiperazinocarbonyl)	same
15	(5S)	Carbamoyl pyrrolidin-4-ylthio	same
16	(5S)	Dimethylaminocarbonyl	same
17	(5S)	(1-pyrrolidino)carbonyl	same
18	(5S)	(1-Azatidino)carbonyl	same
19	(5S)	(2-Hydroxyethyl)methylaminocarbonyl	same
20	(5S)	(1-Morpholinocarbonyl)	same
21	(5S)	(1-N-Methylpiperazinocarbonyl)	same
22	(5S)	Carbamoyl pyrrolidin-4-ylthio	same

How dependent stereochemical claims broaden beyond 5R/5S

Claims 25–28: carve out (5R) and (5S) compounds “represented by” additional formulas, plus higher stereochemistry variants:
- 27–28 claim (5R,6S,8R) and (5S,6S,8R) compounds (dependent to claim 22 and/or others).
Claims 29–34: extend to (5R,6S,8R,2’S,4’ S) and (5S,6S,8R,2’S,4’S) variants.
Claims 38–39: add additional stereochemical enumerations:
- Claim 38: (5S) compound as claimed in claim 8, represented by another formula.
- Claim 39: (4R,5S,6S,8R,2’S,4’S) compound as claimed in any one of claims 2, 8, 18, 19, 20, 21, or 22.

Implication for freedom-to-operate (FTO). Even if a competitor avoids matching the “Y” sidechain exactly, the dependent stereochemical layers can still trap close analogs where the stereochemical pattern matches and the scaffold positions remain within claim-defined variable parameters.

Do claims 23–24 create additional barriers via composition and method-of-use protection?

Short answer. Yes. Claim 23 covers antimicrobial pharmaceutical compositions with the patented β-lactams as active ingredient; claim 24 covers a method of treating bacterial infection by administering an effective amount of those compounds.

Claim 23: composition

A pharmaceutical composition for antimicrobial use comprises:
- at least one compound of claim 1 or 2,
- plus at least one pharmaceutically acceptable inert carrier/diluent.

This is a typical barrier to direct generic entry where the generic product’s label or formulation must avoid infringing “antimicrobial use composition” coverage, though in practice the force depends on product-specific composition and labeling.

Claim 24: method of treatment

A method of treating a bacterial infection by administering an effective amount of claim 1 or 2 compound.

For litigation risk, method claims often become relevant where a competitor’s product label includes the claimed method and where infringement theories target induced/direct infringement in the U.S.

What other independent formula claims (35–37) and how do they tighten “Y” coverage?

Short answer. Claims 35–37 are additional β-lactam formula claims that again use the scaffold framing but with Y constrained to enumerated groups (chosen from specific sets), creating a second tier of coverage beyond the broad Markush definitions in 1–2.

Claim set

Claim 35: β-lactam formula with Y chosen from one set (formula block shown).
Claim 36: β-lactam formula with Y chosen from another set.
Claim 37: β-lactam formula with Y chosen from yet another set.

Implication. Even if a competitor attacks the Markush breadth by arguing the “Y” is outside formula (2), they still face risk if their compound matches the specific “Y chosen from” groups of claims 35–37.

What is the patent landscape for U.S. Patent 4,943,569: how do you map claim scope to likely infringement/avoidance strategies?

Short answer. Without bibliographic and prosecution data in the prompt (filing date, assignee, prosecution history, related family members, and citations), a complete “landscape” (forward citations, family continuations, terminal disclaimers, and litigation events) cannot be generated. Still, the claim architecture itself points to the most relevant competitive design-arounds and the main infringement vectors.

Infringement vectors

Core scaffold match: The competitor’s β-lactam must align with the azabicyclic β-lactam framework and carboxylic acid architecture.
R1 match: Must include 6-(1-hydroxyethyl) or protected-hydroxy variant.
X match: Unsubstituted methylene (claim 1) vs alkyl substituted methylene with R4 C1–C3 (claim 2).
Y match: Must fall inside the defined substituted ring-forming amino/heteroatom-linked cyclic amino family via R5/R6 rules.
Stereochemistry match: Dependent claims can catch stereospecific variants even when some genus parameters are borderline.

Design-around routes most likely to matter

Break “X” coverage by altering X away from:
- unsubstituted methylene (claim 1) and
- alkyl substituted methylene with R4 restricted to C1–C3 (claim 2).
Move “Y” outside R5/R6 rules by using sidechains not forming the allowed cyclic amino sizes or not carrying permitted substituents (hydroxyl, di(C1–C3)alkylamino, or carbamoyl) in the enumerated ways.
Remove the 1-hydroxyethyl motif or substitute it with a different alcohol/chain length that is not within R1’s “1-hydroxyethyl (free or protected)” definition.
Avoid stereochemical combinations if dependent stereocenter claims are asserted; however, avoiding by stereochemistry only works if it also exits the corresponding “represented by” formula boundaries.

How do the claims compare with typical β-lactam patent families (genus Markush + stereochemical + formulation/method claims)?

Short answer. U.S. 4,943,569 follows a classic optimization pattern:

broad genus at the scaffold and sidechain level (claims 1–2),
species enumeration for specific sidechains and stereoisomers (claims 10–22),
composition and treatment claims (claims 23–24),
and stereochemistry expansion through dependent “(5R)/(5S)/(5R,6S,8R)/(5S,6S,8R)/(5R,6S,8R,2’S,4’S)/(5S,6S,8R,2’S,4’S)” families (claims 25–34, 38–39).

Operational effect: infringement tends to be pleadable under either genus or narrow species depending on how closely a challenger matches the exact enumerated sidechain and stereochemistry.

Key takeaways

U.S. Patent 4,943,569 claims a constrained β-lactam scaffold with a 6-(1-hydroxyethyl) motif and a sidechain Y defined by R5/R6 ring-forming cyclic amino rules.
The broadest independent claims (1–2) hinge on:
- X methylene being either unsubstituted (claim 1) or alkyl-substituted with R4 C1–C3 (claim 2),
- plus Y within the R5/R6-defined cyclic amino family and salts.
The patent then adds specific (5R) and (5S) species (claims 10–22) covering multiple carbonyl-linked cyclic amino sidechains such as pyrrolidino, azetidino/azatidino, morpholino, N-methylpiperazinyl, carbamoyl, dimethylamino carbonyl, and hydroxyethyl methylamino carbonyl.
Composition (claim 23) and method-of-treatment (claim 24) claims expand the enforcement surface beyond chemical structure, tying infringement to antimicrobial formulations and bacterial infection treatment use.
Dependent stereochemical “compound of” claims (25–34, 38–39) increase the odds that close analogs matching correct stereocenters still fall within claim coverage.

FAQs

If a competitor changes only the sidechain Y ring size, does U.S. 4,943,569 still read on it?
Likely yes if the alternative ring still fits the R5/R6 cyclic amino formation rules (including the allowed 4–7-membered range and permitted substituents) and the scaffold and X/R1 match.
What is the cleanest claim boundary between claim 1 and claim 2?
The “X” position: unsubstituted methylene (claim 1) versus substituted methylene with R4 = C1–C3 alkyl (claim 2).
Do protected-group allowances expand coverage to intermediate forms?
Yes for R1 (hydroxy protected), R2 (amino protected), and R3 (carboxyl protected) as written in the genus definitions.
How do the dependent stereochemistry claims affect non-infringement by stereoselective synthesis?
They can; dependent “(5R)/(5S)/(5R,6S,8R)...” claims capture specific stereochemical patterns, so avoiding the exact stereochemistry referenced can matter if the “represented by” boundaries are matched.
Can generics avoid infringement by using a different formulation carrier while keeping the same active ingredient?
Claim 23 still covers a composition with the patented compound plus an inert carrier/diluent; formulation carrier changes alone do not avoid infringement if the active ingredient remains within claims 1–2 and the composition is for antimicrobial use.

References

No references can be produced from the information provided in the prompt.

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Japan	58-081443	May 09, 1983
Japan	58-108472	Jun 15, 1983
Japan	58-127485	Jul 12, 1983
Japan	58-166938	Sep 09, 1983

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0126587	⤷ Start Trial	SPC/GB95/030	United Kingdom	⤷ Start Trial
European Patent Office	0126587	⤷ Start Trial	96C0023	Belgium	⤷ Start Trial
Austria	121402	⤷ Start Trial
Bulgaria	60499	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 4,943,569

Summary for Patent: 4,943,569