Invalidity dossier
US 5831089
Process to produce midazolam
Current assignee: Pharmacia and Upjohn Co
Added 9/23/2026, 7:51:51 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: US5831089A
Title: Process to produce midazolam
Patent number: US5831089A
Application number: US08/864,043
Inventor: Joel E. Huber
Original/current assignee: Pharmacia and Upjohn Co
Priority date: 1996-07-01
Filing date: 1997-05-28
Publication (grant) date: 1998-11-03
Anticipated expiration: 2017-05-28
Legal status (as listed): Expired – Fee Related
Purpose
The patent concerns a manufacturing process for producing midazolam, a benzodiazepine drug. According to the supplied abstract-level text, the process prepares midazolam from a benzophenone starting material via intermediates, and references a preparation method and an intermediate.
Plain-language scope (from the supplied text)
The excerpt indicates a multi-step chemical process. Key materials associated with the claims/description include midazolam, acetonitrile, dichloromethane, 1H-1,2-benzodiazepine, benzodiazepine, N,N-dimethylformamide, solvents, toluene, molecular sieves, and sodium aluminosilicate. Described reagents and techniques include ethyl acetate, methanol, isopropanol, acetic acid, dimethyl sulfoxide, water, ethanol, n-heptane, ammonium hydroxide, tetrahydrofuran, n-hexane, triethylamine, hydroxylamine, manganese dioxide, lithium diisopropylamide, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, tetramethylsilane, oxalic acid, and sodium acetate, alongside thin-layer chromatography, high-performance liquid chromatography, NMR spectroscopy, IR spectroscopy, fast atom bombardment, vacuum filtration, and silica-gel purification.
Named chemical entities in the text include (2-amino-5-chlorophenyl)-(2-fluorophenyl)methanone, 7-chloro-5-(2-fluorophenyl)-2-(nitromethylidene)-1,3-dihydro-1,4-benzodiazepine, and a benzodiazepine N-oxide species. The text also lists related filings US5942614A and US5922892A claiming priority to the same application family.
Source: https://patents.google.com/patent/[US5831089](/patent/US5831089)/en
What the excerpt does not establish
The supplied text is partial. It does not provide the actual numbered claims, full claim language, dependent-claim structure, or claim limitations. It does not give complete example procedures, yields, purities, temperatures, molar ratios, or reaction conditions. It does not identify the specific prior-art references relied upon. It does not establish legal status conclusions, enforceability, validity, or the accuracy of assignee listings, and no litigation or ownership-transfer information is included.
Generated 10/1/2026, 9:41:45 PM
Cases on file (0)
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Litigation summary
Past and pending lawsuits — plaintiffs, defendants, jurisdictions, outcomes, and notable rulings.
Proceedings on file (0)
All PTAB activity →AIA trial proceedings (IPR / PGR / CBM) filed at the USPTO Patent Trial and Appeal Board against this patent. Sourced from the USPTO Open Data Portal and refreshed every six hours; each proceeding number deep-links to the PTAB E2E docket.
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.