US 8404618B2

US Patent 8404618B2 Summary:

• Title: Herbicidal composition
• Assignee: Syngenta Crop Protection AG Switzerland (Current), Syngenta Ltd (Original).
• Inventors: Andrew Plant, Willy Thaddaeus Rüegg, Jean Wenger, Ulrich Johannes Haas, Anja Greiner.
• Filing Date: April 29, 2005.
• Issue Date: March 26, 2013.
• Abstract: A herbicidal composition comprising a compound of formula (I) (where substituents have meanings as given in claim 1) and a safener.

Plain-Language Overview of Independent Claims:

The patent claims a herbicidal composition designed to combat weeds and weed grasses in useful crop plants without damaging the crops. The core of the invention lies in a mixture of two main components:

• Claim 1 (Independent): This claim defines a herbicidal composition. It must include:

  • A herbicidally active amount of a herbicide described by Formula I. This formula has several variable components (R1, R2, R3, R4, R5, R6, m, n, and Y) which are broadly defined, allowing for a wide range of specific herbicide compounds. For example, R1 and R2 can be independently C1-C10 alkyl or C3-C8 cycloalkyl, or form a C3-C7 ring together with the carbon atom they are bonded to. M can be 0, 1 or 2, and n can be 1, 2 or 3. Y can be various substituted phenyl or heterocyclic aromatic rings.
  • A herbicide-antagonistically active amount of a safener chosen from a group of ten general formulas (S-I to S-X). These safener formulas also have variable substituents (e.g., Xs1, Rs1, Rs2, etc.). For instance, safener S-I features Xs1 as hydrogen or halogen and Rs1 as hydrogen, various alkyl, alkenyl, or cycloalkyl groups, or specific cations.

• Claim 13 (Independent): This claim describes a method for combating weed grasses and weeds in useful crop plants. This method involves treating the plants, their seeds, cuttings, or the growing area with:

  • A herbicidally active amount of the herbicide of Formula I (as described in Claim 1).
  • A herbicide-antagonistically active amount of a safener of formulas S-I to S-X (as described in Claim 1).
  • The treatment can occur simultaneously or at separate times.

CAFC 2026 Dockets:

A search of CAFC 2026 dockets did not return any cases specifically mentioning patent number US8404618B2. The search results provided general information about CAFC activity in 2026, including summaries of other patent-related appeals and dismissals for lack of appellate jurisdiction. Therefore, there is no authoritative information available indicating active litigation for this specific patent in the CAFC dockets for 2026 as of April 26, 2026.

As of April 26, 2026, there is no known litigation involving US patent 8404618B2 found in a search of the Unified Patents litigation portal or general PACER searches. The search results provided did not mention this specific patent number in the context of any legal proceedings.

Proceedings overview

A single AIA trial proceeding, IPR2017-01332, was filed against US Patent 8404618B2. This proceeding concluded with institution being denied, meaning no claims were reviewed on the merits. This outcome leaves all claims of US8404618B2 intact, indicating a hardened defensive posture for the patent owner, as the patent has successfully resisted an IPR challenge.

IPR2017-01332 — Bayer CropScience LP v. Syngenta Limited

• Type: Inter Partes Review
• Filed: 2017-04-28
• Status: Institution Denied. The PTAB declined to institute the inter partes review, meaning the merits of the patentability challenge were not fully adjudicated, and the challenged claims remain patentable.
• Judge panel: Zhenyu Yang, Christopher G. Paulraj, and Robert A. Pollock (Administrative Patent Judges).
• Petition grounds: Bayer CropScience LP challenged claims 1-5 and 7-12 of US8404618B2, alleging unpatentability based on anticipation (§ 102) and obviousness (§ 103). The primary prior art references cited were "Polge" (consisting of the Polge Patent (Ex. 1008) and Polge Publication (Ex. 1009)) and Owen, with additional references for obviousness grounds. Petitioner also raised a contention regarding lack of entitlement to the priority date, arguing new matter was introduced, which would make references like Takahashi prior art.
• Institution decision: Denied on 2017-11-06. The Board determined that the Petitioner had not shown a reasonable likelihood of prevailing with respect to at least one of the challenged claims. Key to the denial was the PTAB's finding that Petitioner failed to show that a skilled artisan would have understood "KIH-485" (a herbicide mentioned in the Owen reference) to be pyroxasulfone prior to the '618 patent's filing date. The Board also addressed a request for rehearing by Bayer CropScience LP, which was denied on 2018-04-02, reiterating that post-filing evidence cannot be used to identify a chemical structure known only by an experimental code name in prior art.
• Final Written Decision: Not applicable, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: Not applicable, as institution was denied.
• Defensive value: This IPR denial significantly strengthens the defensive posture of US8404618B2. All challenged claims (1-5 and 7-12) were not found to be unpatentable in this proceeding, and the patent owner successfully defended against the petition. An IPR-based defense using the same or similar prior art and arguments will face an uphill battle, especially given the PTAB's specific reasoning regarding the identification of chemical structures from experimental code names.

Strategic summary

All claims of US8404618B2 remain SUSTAINED and UNTESTED on the merits, as the sole IPR filed against it (IPR2017-01332) was denied institution. The petition specifically challenged claims 1-5 and 7-12. Since institution was denied, these claims were not found unpatentable, nor were they modified or canceled. This implies that claims 6, and 13-30 remain entirely untested by an AIA trial proceeding.

Regarding the estoppel landscape, § 315(e)(2) estoppel would apply to Bayer CropScience LP (and its privies) for any grounds raised or that reasonably could have been raised in IPR2017-01332 against claims 1-5 and 7-12. However, for a new defendant, the prior art grounds (Polge, Owen, Takahashi, and combinations) that were presented in the petition but failed to persuade the Board for institution are generally still available to be raised in district court litigation. The PTAB's reasoning for denying institution, particularly concerning the identification of KIH-485 as pyroxasulfone in Owen, provides insight into potential weaknesses of those prior art arguments.

This patent has a strong defensive signal from the PTAB perspective. The absence of further IPR challenges after a denial of institution for the first one suggests that potential petitioners may have evaluated the patent and the IPR institution decision and found the prospects of success low, or have chosen alternative strategies. The patent owner, Syngenta Limited (now Syngenta Crop Protection AG), successfully defended against this challenge.

Recommended next steps

Since IPR2017-01332 was denied institution, there is no Final Written Decision to link to for claim cancellation. However, the decision denying institution is public. For reference, the Decision Denying Institution of Inter Partes Review, Paper No. 10, was entered on 2017-11-06. The Petitioner also filed a Request for Rehearing, which was denied on 2018-04-02 (Paper No. 15). These documents would be crucial for understanding the PTAB's reasoning.

Currently, there are no active PTAB proceedings pending against US8404618B2. This indicates that the patent has successfully weathered its only public IPR challenge to date, making an IPR-based defense more challenging for future litigants, particularly if they intend to rely on the same prior art and arguments.

Inventors

• Andrew Plant
• Willy Thaddaeus Rüegg
• Jean Wenger
• Ulrich Johannes Haas
• Anja Greiner

The inventors were likely employed by Syngenta Ltd, the original assignee, at the time of filing.

Original assignee

• Name: Syngenta Ltd
• Products: Syngenta is a global agribusiness company known for producing agrochemicals (herbicides, insecticides, fungicides) and seeds. It is highly probable they shipped products embodying the claims of this herbicidal composition patent.
• Primary Line of Business: Agribusiness, focusing on crop protection and seeds.
• Current Status: Syngenta Ltd is part of the larger Syngenta Group, which is an active and operating entity.

Assignment timeline

• 2025-04-24 (executed) / recorded 2025-05-01 — Reel 071458/0501

  • Conveyance: Assignment
  • Assignor: SYNGENTA PARTICIPATIONS AG
  • Assignee: SYNGENTA CROP PROTECTION AG
  • Correspondent: SYNGENTA CROP PROTECTION AG, CH-4002 BASEL, SWITZERLAND. This correspondent will recur in this chain.
  • Context: internal reorg (Merger, as indicated by Google Patents legal event).

• 2025-04-24 (executed) / recorded 2025-05-01 — Reel 071145/0565

  • Conveyance: Assignment
  • Assignor: SYNGENTA PARTICIPATIONS AG
  • Assignee: SYNGENTA CROP PROTECTION AG
  • Correspondent: SYNGENTA CROP PROTECTION AG, CH-4002 BASEL, SWITZERLAND. This is the same correspondent as the previous entry.
  • Context: internal reorg (Correction, likely a re-confirmation of assignment or a corrective filing related to an earlier record removal, as indicated by Google Patents legal event for 2025-09-30 referring to this reel/frame).

Timeline diagram

timeline
    title Ownership of US 8404618B2
    2005 : Filed by Syngenta Ltd
    2013 : Issued to Syngenta Ltd
    2025 : Assigned to Syngenta Crop Protection AG
         : Corrective assignment to same

NPE / troll-pattern signals

1. Shell-entity transfer: Not present. The assignor (SYNGENTA PARTICIPATIONS AG) and assignee (SYNGENTA CROP PROTECTION AG) are known operating entities within the global Syngenta Group.
2. Known asserter in the chain: Not present. Syngenta is a major operating company in the agribusiness sector, not a known non-practicing entity.
3. Repeat correspondent across the chain: Present. The correspondent "SYNGENTA CROP PROTECTION AG, CH-4002 BASEL, SWITZERLAND" appears on both recorded assignments (Reel 071458/0501 and Reel 071145/0565, recorded 2025-05-01). This recurrence, however, is for internal corporate transfers within a large operating group.
4. Cascading transfers: Not present. The two recorded assignments occurred on the same date with the same parties, indicating a single, consolidated internal corporate action rather than multiple consecutive transfers through different entities.
5. Pre-litigation transfer: Not present. The assignments occurred in 2025. No litigation was found in CAFC dockets for 2026 as of April 26, 2026 (per prior analysis).
6. Bankruptcy fire-sale: Not present. There is no indication of bankruptcy proceedings for the assignor or original assignee.
7. Privateering: Not present. The patent remains within the Syngenta operating group.
8. Defensive aggregator (anti-NPE): Not present. The current assignee is an operating company.

Verdict

Operating-company assertion. The patent was filed by Syngenta Ltd and subsequently transferred internally to Syngenta Crop Protection AG (Reel 071458/0501 and Reel 071145/0565, both recorded 2025-05-01), both of which are operating entities within the Syngenta Group. These assignments represent an internal corporate reorganization and not a transfer to a non-practicing entity.

Verification: https://assignmentcenter.uspto.gov/ (search for patent 8404618).

To identify the most relevant prior art for US patent 8404618B2, I will use the information available on Google Patents and the USPTO's Patent Public Search. The patent document itself typically lists "U.S. Patent Documents" and "Foreign Patent Documents" as prior art. I will extract these and analyze their potential anticipation.

Based on the patent text, several prior art documents are explicitly mentioned as describing known safeners (formulas S-I to S-X) or the isoxazoline herbicides (formula I).

Here's an analysis of the prior art explicitly cited within US8404618B2:

Prior Art Relating to Safeners (S-I to S-X):

The patent states that the safeners of formulas S-I to S-X are known and described in various patents. These include:

• U.S. Pat. No. 5,041,157
• U.S. Pat. No. 5,541,148
• U.S. Pat. No. 5,006,656
• EP-A-0 094 349
• EP-A-0 551 650
• EP-A-0 268 554
• EP-A-0 375 061
• EP-A-0 174 562
• EP-A-492 366
• WO 91/7874
• WO 94/987
• DE-A-19612943
• WO 96/29870
• WO 98/13361
• WO 98/39297
• WO 98/27049
• EP-A-0 716 073
• EP-A-0 613 618
• U.S. Pat. No. 5,597,776
• EP-A-0430 004
• WO 97/45016
• WO 99/16744
• WO 03/02205

And specifically for cloquintocet-mexyl salts:

• WO 02/34048

Prior Art Relating to Isoxazoline Herbicides:

The patent also references documents describing the class of isoxazoline herbicides, such as those of formula I:

• WO 01/12613
• WO 03/000686
• WO 2004/014138
• JP (Kokai) 2004-2324

To provide a brief description and identify potentially anticipated claims under 35 U.S.C. § 102, a detailed review of each cited patent would be required. However, based on the description within US8404618B2, the relevance of these prior art documents can be summarized:

General Prior Art Categories and Potential Anticipation:

The core of US8404618B2 lies in the combination of specific isoxazoline herbicides (Formula I) with certain safeners (Formulas S-I to S-X) for synergistic herbicidal activity that protects crop plants.

Therefore, any prior art that discloses:

• A herbicidal composition comprising a compound of Formula I: If a prior art reference fully describes a compound falling under Formula I, this could potentially anticipate elements of Claim 1 related to the herbicide itself, and Claim 13 related to its use. The patent explicitly states that these isoxazoline herbicides are a "certain class" that are "described e.g. in WO 01/12613, WO 03/000686, WO 2004/014138 and JP (Kokai) 2004-2324." This suggests that the herbicides alone may be known in the prior art.
• A safener of Formula S-I to S-X: The patent explicitly states, "The safeners of the formulae S-I to S-X are known and are described e.g. in U.S. Pat. No. 5,041,157, U.S. Pat. No. 5,541,148, U.S. Pat. No. 5,006,656," and many other patent documents. This means the safeners themselves are known compounds. These documents would anticipate the individual safeners, but not necessarily their combination with the specific herbicides of Formula I in a herbicidal composition.
• A herbicidal composition combining any isoxazoline herbicide with any safener from S-I to S-X: This would be highly relevant and could potentially anticipate Claims 1 and 13 if the combination taught in the prior art is substantially the same as or renders obvious the claimed invention.

Under 35 U.S.C. § 102, a claim is anticipated if every element of the claim is disclosed, either explicitly or inherently, in a single prior art reference. Given that both the herbicides of Formula I and the safeners of Formulas S-I to S-X are described as "known" individually in the cited prior art, the most critical aspect for anticipation of Claims 1 and 13 would be whether any single prior art reference explicitly discloses the combination of a herbicide of Formula I with a safener from S-I to S-X, and its herbicidally active and herbicide-antagonistically active amounts for the intended purpose. Without examining the full text of each referenced prior art document, it is not possible to definitively state which claims are anticipated. However, it is probable that these references individually anticipate the components (herbicide or safener) as compositions of matter. The inventive step would likely reside in the specific combination and its demonstrated efficacy.

The obviousness analysis under 35 U.S.C. § 103 for US Patent 8404618B2 requires identifying prior art combinations that would have made the claimed herbicidal compositions or methods obvious to a person having ordinary skill in the art (POSITA) at the time of the invention (before April 30, 2004, the priority date). The core of the invention is a herbicidal composition comprising a herbicide of Formula I and a safener from formulas S-I to S-X.

General Principles of Obviousness for Herbicidal Compositions with Safeners:

A POSITA in agrochemical formulation would have been aware of the common problem of crop damage caused by herbicides and the existence of safeners to mitigate this damage. Safeners were known to increase crop tolerance to herbicides without reducing weed control efficacy, primarily by accelerating herbicide metabolism and detoxification in the crop plants. The use of safeners with various herbicide classes, including sulfonylureas, imidazolinones, cyclohexanediones, and isoxazolidinones, was also known. This general knowledge would have motivated a POSITA to combine new herbicides with known safeners to achieve selective weed control in crops.

Analysis of Claims and Prior Art:

Claim 1 (Herbicidal Composition): This claim defines a composition comprising a herbicide of Formula I and a safener from S-I to S-X.

• Herbicides of Formula I: The patent states that the herbicides of Formula I are a "certain class of isoxazoline herbicides which are described e.g. in WO 01/12613, WO 03/000686, WO 2004/014138 and JP (Kokai) 2004-2324." Isoxazoline-containing molecules were known to have herbicidal activity, including as protoporphyrinogen oxidase (PPO) inhibitors, VLCFA inhibitors, and 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors. WO 2004/014138 explicitly discloses herbicide compositions containing an isoxazoline derivative of a general formula (similar to Formula I in US8404618B2) or a salt thereof. This indicates that the herbicide compounds of Formula I, or at least a similar class of isoxazoline herbicides, were known in the prior art.
• Safeners of Formulas S-I to S-X: The patent itself states that "The safeners of the formulae S-I to S-X are known and are described e.g. in U.S. Pat. No. 5,041,157, U.S. Pat. No. 5,541,148, U.S. Pat. No. 5,006,656, EP-A-0 094 349, EP-A-0 551 650, EP-A-0 268 554, EP-A-0 375 061, EP-A-0 174 562, EP-A-492 366, WO 91/7874, WO 94/987, DE-A-19612943, WO 96/29870, WO 98/13361, WO 98/39297, WO 98/27049, EP-A-0 716 073, EP-A-0 613 618, U.S. Pat. No. 5,597,776, EP-A-0430 004, WO 97/45016, WO 99/16744 and WO 03/02205." This explicit admission in the patent's description means that these safeners were individually known in the prior art. Furthermore, specific examples of safeners listed as "particularly preferred" in US8404618B2, such as cloquintocet-mexyl, fenchlorazole-ethyl, mefenpyr-diethyl, isoxadifen-ethyl, furilazole, benoxacor, dichlormid, MON4660, oxabetrinil, cyometrinil, fenclorim, naphthalic acid anhydride, and flurazole, are all recognized as established herbicide safeners in the broader agricultural chemical literature.

Obviousness Combination:

A strong case for obviousness can be made by combining the knowledge of isoxazoline herbicides (as disclosed in WO 01/12613, WO 03/000686, WO 2004/014138, and JP (Kokai) 2004-2324) with the known safeners (S-I to S-X) that were extensively documented in various patents and publications prior to the priority date of US8404618B2.

• Motivation to Combine: A POSITA would have been motivated to combine a new herbicide, such as the isoxazoline derivatives of Formula I, with a known safener (S-I to S-X) for several reasons:
  1. Addressing Crop Phytotoxicity: The primary motivation for using safeners is to protect crop plants from herbicide injury while maintaining effective weed control. This is a long-standing problem in agriculture that safeners are specifically designed to solve.
  2. Expanding Herbicide Utility: Safeners allow for the use of herbicides that might otherwise be too phytotoxic to crops, or to expand the use of existing herbicides to new crops or application methods. Given the continuous development of new herbicide compounds, it would be a natural and logical step for a POSITA to evaluate them in combination with established safeners to improve selectivity.
  3. Predictability of Safener Action (to a degree): While the interaction between herbicides and safeners can be complex, and predicting specific interactions isn't always straightforward, the general mechanism of safeners (accelerating herbicide metabolism in crops) was understood. This understanding would encourage routine experimentation with known safeners in conjunction with new herbicide chemistries. For instance, isoxadifen-ethyl was known to safen herbicides of various modes of action.
  4. Commercial Viability: The commercial success of herbicide-safener products would further motivate research and development in this area.

Example Combination for Obviousness of Claim 1:

Consider a combination of WO 2004/014138 and U.S. Pat. No. 5,041,157.

• WO 2004/014138: This patent explicitly describes herbicide compositions containing an isoxazoline derivative of a general formula, which is the class of herbicides defined by Formula I in US8404618B2.
• U.S. Pat. No. 5,041,157: This patent (and numerous others cited in US8404618B2 for S-I to S-X) describes and claims a safener, for instance, a compound that falls within the scope of Formula S-I. For example, cloquintocet-mexyl, a preferred safener of formula S-I.1 in US8404618B2, was a known safener.

A POSITA, upon encountering the isoxazoline herbicides in WO 2004/014138, and facing potential crop phytotoxicity issues, would have been motivated to combine them with a known safener such as those disclosed in U.S. Pat. No. 5,041,157 to achieve selective weed control. This combination would be a logical extension of existing agricultural practices and known chemical properties of both herbicides and safeners.

Claim 13 (Method of Combating Weeds): This claim describes a method involving treating plants or their growing area with the herbicide of Formula I and a safener from S-I to S-X, either simultaneously or at separate times.

• Obviousness based on Claim 1 obviousness: If the composition of Claim 1 is obvious, then the method of using that obvious composition in a standard manner for weed control would also be obvious.
• Established Methods of Application: The patent itself describes the conventional methods of application, including pre-emergent, post-emergent, and seed dressing, and states that safeners can be applied for pre-treatment of seed, or introduced into soil before or after sowing, or applied by itself or with the herbicide before or after emergence. It also notes that simultaneous application (e.g., as a tank mix) is generally preferred. These methods were well-established in the art of herbicide and safener application.

Example Combination for Obviousness of Claim 13:

Building on the previous combination of WO 2004/014138 (disclosing the herbicide) and U.S. Pat. No. 5,041,157 (disclosing the safener):

A POSITA would know to apply such a herbicide-safener combination using conventional agricultural practices. The knowledge that safeners are used to protect crops from herbicide injury (as discussed above) and the various methods of applying safeners (seed treatment, pre-emergence, post-emergence, simultaneous or separate application) were well-known. Therefore, applying the known isoxazoline herbicide with a known safener using conventional methods would be an obvious step to achieve the desired selective herbicidal effect.

Conclusion on Obviousness:

Given the explicit admissions in US8404618B2 that the safeners of formulas S-I to S-X are known and the references to prior art describing the class of isoxazoline herbicides, the combination of these known elements to form the claimed herbicidal compositions and methods would have been obvious to a person having ordinary skill in the art at the time of the invention. The motivation to combine would stem from the long-standing problem of crop phytotoxicity and the established practice of using safeners to improve herbicide selectivity and expand their utility in agriculture.