Invalidity dossier
US 5098925
Spiro-dihydroisoindole compounds
Current assignee: Zeneca Inc
Added 9/23/2026, 9:52:52 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US5098925A
Title: Spiro-dihydroisoindole compounds
Patent number: US5098925A
Application number: US07/650,503
Inventor: Thomas M. Bare
Original assignee: ICI Americas Inc.
Current assignee (as listed): Zeneca Inc.
Priority date: 1990-02-08
Filing date: 1991-02-05
Publication (grant) date: 1992-03-24
Legal status (as listed): Expired – Fee Related; anticipated expiration 2011-02-05
Purpose / plain-language scope (from the supplied text):
The patent concerns a class of chemical compounds termed "spiro-dihydroisoindole compounds," together with methods, pharmaceutical compositions, and intermediates. The disclosed subject matter is associated with N-methyl-D-aspartate (NMDA) receptors and phencyclidine receptors, and with antagonist activity; the text also associates the compounds with neurological disease, nervous system disease, and ischemic effects such as stroke, and with testing methods and synthesis. Claim-level keywords indicate the chemical scope centers on spiro-dihydroisoindole structures bearing substituents such as hydrogen, alkyl groups (methyl, ethyl, propyl, butyl, pentyl, and branched variants including isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl), alkoxy groups (methoxy, ethoxy, propoxy, isopentoxy), halogen (fluoro, chloro), trifluoromethyl, benzyl, and related groups, and salts thereof. One named compound in the text is 2-methylspiro[1H-isoindole-3,4'-6,7-dihydro-5H-1-benzothiophene]. The text further references mammals and pharmaceutical compositions with diluting agents.
Source: https://patents.google.com/patent/[US5098925](/patent/US5098925)/en
What the excerpt does not establish:
The supplied excerpt is incomplete and boilerplate-heavy. It does not provide the full claim language, the complete specification, the detailed description, working examples, dosages, or the exact chemical definitions of the Markush variables. It does not establish the identity of any prior art, the validity or enforceability of any claim, litigation history, or the accuracy of the listed assignees, legal status, or dates, which the source itself labels as assumptions. It also does not establish any therapeutic efficacy, approval, or commercial status. No such facts should be inferred from this overview.
Generated 10/1/2026, 9:33:58 PM
Cases on file (0)
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Litigation summary
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Proceedings on file (0)
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No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
Earlier patents, publications, and products that may anticipate or render the claims unpatentable.
Obviousness
Combinations of prior art that suggest the claimed invention would have been obvious under 35 U.S.C. § 103.
Extensions
Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.
Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.