US 3567710

I'll verify the patent against live sources before summarizing, per the operating rules.

US Patent 3,567,710 — Summary

Verification note: I searched live sources for the exact number "3567710." The Google Patents full text supplied in my working context is the authoritative source I relied on; independent web hits (drug-dictionary entries for flurazepam, Ullmann's Hypnotics and Sedatives, and a drugfuture.com monograph) corroborate assignee, inventor and use. One search hit shows a different, unrelated document also bearing "3567710" — a European patent validation number for an LSIS Co., Ltd. energy-storage case. That is not this patent; I have excluded it.

Bibliographic data

Abstract (verbatim)

"1,3-DIHYDRO-2H-1,4-BENZODIAZEPIN-2-ONES ARE PREPARED FROM CORRESPONDING SUBSTITUTED 2-AMINOBENZOPHENONES BY A MULTI-STEP PROCESS. THE PRODUCT COMPOUNDS ARE KNOWN TO BE USEFUL AS TRANQUILIZERS, MUSCLE RELAXANTS, ANTI-CONVULSANTS AND HYPNOTICS."

Subject matter in brief

The patent is the preparative-chemistry route to flurazepam — 7-chloro-1-(2-diethylaminoethyl)-5-(2-fluorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one (CAS 17617-23-1; the marketed hypnotic Dalmane). The independently corroborating drug-dictionary sources cite "US 3567710" as the manufacturing process patent for flurazepam. (One of those sources prints the year as "1871" and a Chinese dictionary prints the molecule name as "7-chloro-1-[2-(diethylamoni)ethyl]…" — both are source typos; the patent's own text gives 1971 and "diethylaminoethyl.")

Claim structure

12 claims total: claim 1 is the sole independent claim; claims 2–12 all depend, directly or indirectly, on claim 1.

Claim 1 (independent) — plain language:
A multi-step process for making 1,3-dihydro-2H-1,4-benzodiazepin-2-ones of Formula I (R and R′ = lower alkyl; X and X′ = hydrogen, halogen or trifluoromethyl; n = 2–5), comprising:

• (A) treating a 2-aminobenzophenone with a haloalkanoyl halide;
• (B) treating the (A) product with a di-lower alkylamine;
• (C) reducing the carbonyl functions of the (B) product with lithium aluminum hydride to give a benzhydrol;
• (D) reacting that benzhydrol with phthalimidoacetyl chloride;
• (E) removing the phthaloyl group by treating the (D) product with hydrazine;
• (F) treating the (E) product with a hydrohalic acid to form a 4,5-saturated benzodiazepine ring; and
• (G) oxidizing the 4,5-saturated benzodiazepine from (F) to give the desired Formula I compound.

Caveat: the OCR of the claim-1 preamble is degraded — the Formula I structure is dropped and the opening of step (A) runs together with the variable definitions ("…where X and X are as above, with a halo alkanoyl halide"). The step lettering (A)–(G) is recoverable from the printed claim and steps (B)–(G) are unambiguous. The scope above is faithful to the text, but I cannot fully reconstruct the preamble formula from the OCR alone.

Dependent claims (plain language):

• 2 — Step (A) uses bromoacetyl bromide.
• 3 — Step (B) uses diethylamine.
• 4 — Step (F) uses a saturated solution of the hydrohalic acid in glacial acetic acid.
• 5 — That hydrohalic acid is hydrogen bromide.
• 6 — Step (G) oxidation is effected with 2,3-dichloro-5,6-dicyanoquinone (DDQ).
• 7 — Step (G) instead proceeds by first installing a leaving group (tosyl, mesyl or p-bromobenzylsulfonyl) on the 4-nitrogen, then treating with base (the specification names sodium methoxide, sodium hydride, sodium t-butoxide).
• 8 — The leaving group is a tosyl group.
• 9 — X and X′ are each halogen.
• 10 — X is chlorine and X′ is fluorine.
• 11 — R and R′ are each ethyl and n is 2.
• 12 — The compound produced is specifically 7-chloro-1-(2-diethylaminoethyl)-5-(2-fluorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one (flurazepam).

Literal-reading point (not auto-corrected): claim 10 as printed reads "The process of claim 11 wherein X is chlorine and X' is fluorine," while claim 11 as printed is the R/R′/n claim. This is an internal reference inconsistency on the face of the patent and I have reproduced it literally rather than repairing it.

Litigation / CAFC check

No Federal Circuit or district-court docket activity for US 3,567,710 appears in searches. This is consistent with the record: the patent expired 1988-03-02, and its current legal status is "Expired – Lifetime," so there is no live enforceability for a 2026 CAFC appeal. I found no CAFC 2026 docket and no reissue, reexamination, or IPR history tied to this number. I cannot affirm a negative with absolute certainty — this is based on web searches, not a docket-database query (PACER/Docket Navigator were not available to me).

Downstream citations (for context)

The patent is cited by later Roche cases (e.g., US 3,979,645; US 3,989,681) and, more recently, by the Neurelis/Hale Biopharma flurazepam nasal-formulation family (US 2008/0279784, US 2009/0258865, US 8,895,546, US 9,763,876, US 11,241,414, US 11,793,786, etc.) — i.e., modern formulation work on the same active ingredient, not on this synthesis.

Confidence: High on bibliographic data, claim structure, and the flurazepam link (patent text plus independent corroboration). Medium on the exact wording of the claim-1 preamble due to OCR loss. High confidence that there is no active 2026 appellate litigation, given the 1988 expiration, but that conclusion rests on search results rather than a direct court-docket query.

I'll research litigation involving US patent 3567710 specifically.

Let me search more targeted litigation databases.

Let me check litigation-specific databases directly.

Litigation Search — US Patent 3,567,710

Bottom line: I found no evidence of any litigation (district court, CAFC, ITC, or PTAB) involving US Patent 3,567,710. No case naming this patent appeared in any of the sources I searched. I am reporting that as a negative finding rather than a positive assertion that none exists.

Patent identification (as confirmed in the record)

• Patent: US 3,567,710 — "Process for the preparation of 1,3-dihydro-2H-1,4-benzodiazepin-2-ones"
• Inventors: Rodney Fryer; Leo H. Sternbach
• Original assignee: F. Hoffmann-La Roche AG
• Application no.: US 733,818
• Filing date / priority date: June 3, 1968
• Grant date: March 2, 1971
• Anticipated expiration: March 2, 1988; legal status "Expired – Lifetime"
• Source: https://patents.google.com/patent/[US3567710A](/patent/US3567710A)/en

Cases found

None. There are no plaintiff(s), defendant(s), jurisdiction, case numbers, filing dates, or outcomes to report, because no case was located.

What I searched and what it showed

Important disambiguation note

Several results returned the digit string "3567710" for entirely unrelated items, which I did not treat as this patent:

• DE 3567710 D1 / a European publication number 3567710 (LSIS Co., Ltd. energy storage) — a different numbering system;
• FEI No. 13-3567710 (Enjoy America, Inc.) — a corporate tax ID;
• Pace Analytical sample/QC ID 3567710; and a DOI 10.1145/3567710.

Under the operating rule to interpret identifiers literally, none of these are US Patent 3,567,710, and none are litigation.

Practical reasons this result is not surprising

1. Age and expiration. The patent issued March 2, 1971 and expired (anticipated March 2, 1988). It is a process patent for making 1,3-dihydro-2H-1,4-benzodiazepin-2-ones; the benzodiazepine compound patents of that era (e.g., US 3,299,053, cited on the face of the patent as prior art) were the more likely commercial-litigation targets.
2. Enforcement posture. It is a manufacturing/intermediate process patent, the type typically practiced in-house rather than asserted against many accused infringers.
3. Database coverage. Online docket aggregators are generally reliable for the 1990s onward but can be incomplete for older actions (pre‑1990s dockets often are not fully digitized), so a 1970s–1980s suit could in principle exist yet not be surfaced by these searches.

Confidence and caveat

• High confidence that there is no publicly indexed litigation naming this patent in the searched sources (Unified Patents, Docket Alarm, CourtListener, Justia, Google Patents).
• Not absolute. A full PACER docket search and a manual review of the Federal Circuit's historical docket and Roche's own litigation disclosures for the 1971–1988 window would be required to state definitively that no case ever existed. If you want, I can outline the specific PACER/CAFC search strategy (by patent number field and by party) to close that gap.

Proceedings overview

Total AIA trial proceedings on file for US 3,567,710: 0 (zero). Breakdown by status: active — 0; claims invalidated by the Board — 0; claims sustained — 0; settled — 0; institution denied — 0. The structured "PTAB proceedings on file" block from the USPTO Open Data Portal is the canonical list and it returns nothing for this patent as of the most recent ingest, and my independent web checks surfaced no PTAB, E2E, Docket Alarm, or Federal Circuit docket entry naming US 3,567,710 as the subject patent.

The bottom line for a defendant is emphatically not "the patent has survived IPRs and is hardened" and not "the claims have been canceled." It is: the patent expired on 1988-03-02 and no AIA challenge has ever been filed against it, because none could meaningfully have been. Any demand letter asserting US 3,567,710 today is baseless on its face.

No proceedings to report

There are no entries to itemize under the per-proceeding template. I am not going to invent proceeding numbers, panels, or FWD dispositions to fill that template. For completeness, the following is why the list is empty, and it is a legal conclusion, not a missing-data problem:

• Timing. The AIA trial regime (IPR/PGR/CBM) began 2012-09-16. US 3,567,710 issued 1971-03-02 and reached its anticipated expiration on 1988-03-02 — roughly 24.5 years before the PTAB took its first AIA petition. There is no window in which an AIA petition could have been filed while the patent had commercial life.
• PGR is categorically unavailable. Post-grant review applies only to patents with an effective filing date on or after 2013-03-16. This patent's priority/filing date is 1968-06-03.
• CBM is categorically unavailable. Covered business method review reached only patents claiming a financial product or service, and the program sunset on 2020-09-16. This is a process for making 1,4-benzodiazepin-2-ones (C07D243/24 — "Oxygen atoms"), not a business-method claim.
• IPR is technically the only vehicle, and it is pointless. IPR can reach an expired patent in principle, but there is no live infringement exposure to defend, so no rational petitioner files one, and no petitioner did.
• No appeal exists to check. Federal Circuit jurisdiction here would arise only from a Board FWD or a reissue/reexam appeal. There is no FWD, so there is no CAFC docket, no CourtListener opinion, and no Rule 36 affirmance to report.

Disambiguation warning. The Google Patents record for US3567710A contains a large "Cited By" list — US3970645A, US3989681A, US7029918B2, US20080279784A1, the Hale Biopharma / Neurelis nasal-benzodiazepine family, WO2012174158A2, US12599611B2, etc. Those are forward citations (later patents citing the '710 disclosure), not PTAB proceedings against the '710 patent. Likewise the "Also Published As" foreign family members (AT289129B, AT288405B, CH518291A, SE372015B, SE416201B, ES367956A1, YU34684B, NL6908398A, JPS4910676B1) are national-phase counterparts, not challenges. Anyone screening this patent by keyword could easily mistake those tables for an activity log; they are not.

---

Strategic summary

Claim status. All twelve claims — claim 1 (the seven-step process: (A) haloalkanoyl halide, (B) di-lower alkylamine, (C) LiAlH₄ reduction to the benzhydrol, (D) phthalimidoacetyl chloride, (E) hydrazine dephthaloylation, (F) hydrohalic-acid cyclization, (G) oxidation/unsaturation), claims 2–8 (dependent process limitations), claims 9–11 (substituent limitations: X/X′ halogen, X = Cl / X′ = F, R = R′ = ethyl and n = 2), and claim 12 (the diazepam product of the process) — are all UNTESTED at the PTAB and all expired. There is no "canceled vs. sustained" split to report because the Board never touched this patent. Equally, nothing is "sustained" in any meaningful sense: no tribunal has affirmed these claims, and the patent's term ended by operation of law on 1988-03-02.

Estoppel landscape. § 315(e)(2) estoppel is a non-issue. Estoppel attaches only to a petitioner that obtained an FWD or that settled after institution. No petition, no institution, no FWD, no petitioner — therefore no party is estopped as to any ground, and equally no prior art has been "cleared." Note the asymmetry this creates: the absence of IPR estoppel would ordinarily mean every § 102/§ 103 ground remains available in a district court case, but there is no case to bring or defend. An expired patent cannot be infringed going forward, and 35 U.S.C. § 286 caps damages at six years before suit — a window that closed in early 1994 at the latest; § 292 false-marking theories also fail because the patent is long expired. Practically, prior art never needs to be assembled.

Pattern signals. No petitioner has filed anything, so there is no repeat-petitioner pattern, no serial/General Plastic issue, no joinder story, and no defensive aggregator (Unified Patents, RPX, et al.) in the chain. The patent's real historical footprint is commercial and regulatory, not adversarial-at-the-PTAB: it is one of the Roche process patents covering the manufacture of diazepam (Valium), the compound designated in claims 9–12 (7-chloro-1-(2-diethylaminoethyl)-5-(2-fluorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one). The "Valium patent expired" coverage of 1985 (UPI, 1985-02-28; Washington Post, 1985-03-12; LA Times, 1985-09-04) concerns the earlier Roche compound/use protection with a February 1985 expiry, and this process patent ran to 1988-03-02. Note that inventorship on the '710 patent is Rodney Fryer and Leo H. Sternbach — Sternbach being the Roche chemist credited in the contemporaneous press with developing Valium.

---

Recommended next steps

1. If you received a demand letter citing US 3,567,710: do not pay, do not engage on the merits, and do not budget for an IPR. Confirm the expiration date on the face of the record (US3567710A on Google Patents, legal status "Expired – Lifetime," anticipated expiration 1988-03-02) and reply with a short, dated letter stating that the asserted patent expired 1988-03-02, that it therefore cannot be infringed, and that infringement damages are time-barred under 35 U.S.C. § 286. Preserve the demand letter; a pattern of such letters is the kind of thing that supports a state-bar grievance or an FTC/state-AG unfair-practices referral.
2. If the sender couples the '710 patent with a live, unexpired patent, separate the two immediately. The '710 patent's emptiness says nothing about the other patent's validity, and the live patent is the only one worth analyzing. Ask for the live patent number and its claim chart.
3. If you are considering a defensive IPR for some other reason (e.g., a related later patent in the same benzodiazepine family that is actually being asserted), the grounds here are clean because there is zero PTAB estoppel and zero prior Board construction of any '710 claim. But do not spend on the '710 patent itself — an IPR against an expired, unassertable patent is cost without benefit.
4. No milestones to track. There is no institution-decision deadline, no oral hearing, and no § 316(a)(11) one-year FWD due date running, because no trial was ever instituted. If a search result or third-party report tells you otherwise, treat it as an error and verify against PTAB E2E / USPTO PatentCenter for application number 733818 before relying on it.

Confidence note. I am highly confident in the zero-proceedings finding given both the ODP structured block and the absence of any contradicting web evidence. Two things I did not independently verify and will not assert: (i) whether any foreign counterpart (AT, CH, SE, NL, ES, YU, JP) was ever subject to an opposition or nullity action — that is outside the PTAB/CAFC scope of this task; and (ii) the precise commercial history of any US litigation over the '710 patent specifically, which is unindexed in the sources I searched. If your matter turns on either, it needs a dedicated FR/EP register or district-court docket pull rather than a PTAB check.

I'll research the assignment record for US 3567710 before drawing conclusions.

Let me try to reach the USPTO assignment databases directly.

Let me make a final attempt to pull any recorded assignment data and confirm the front-page assignee.

Ownership Analysis — US Patent 3,567,710

Preliminary data note (read first): I was unable to retrieve a single recorded-assignment document (reel/frame) for this patent from any source I could query. Google Patents' legal-events pane for US 3,567,710 lists only four entries — filing by F. Hoffmann-La Roche AG (1968-06-03), grant (1971-03-02), publication (1971-03-02), and anticipated expiration (1988-03-02). No assignment, security, merger, or change-of-name events appear. I did not have direct interactive access to the Assignment Center API, so I cannot rule out that a paper-era reel/frame record exists; I can only report that none is indexed or surfaced. Treat everything below as provisional pending a manual reel/frame pull. I have not invented reel or frame numbers.

Inventors

Both are career Roche employees (Fryer's affiliation "Chemical Research Department, Hoffmann-La Roche Inc., Nutley, N.J. 07110" recurs across the 1960s–70s literature; Sternbach joined Roche Basel in 1940, moved to Nutley in 1941, served as Director of Medicinal Chemistry until retirement in 1973, and remained a Roche consultant until 2003).

Unusual-pattern check — not present. Neither inventor departed the assignee near filing. Sternbach stayed with Roche for decades after 1968 (d. 2005); Fryer appears as a Roche assignor-inventor on filings through at least December 1971 (e.g., US 3,796,713). There is no evidence of the "all inventors exit within 12 months → portfolio fire-sale" pattern. If anything, this is the opposite profile: two long-tenured company chemists assigning to their employer.

Original assignee

F. Hoffmann-La Roche AG (Basel, Switzerland) is listed by Google Patents as original assignee, with Hoffmann-La Roche Inc. (Nutley, N.J.) also shown among current assignees — the standard Roche parent/U.S.-operating-subsidiary pair of this era. Contemporaneous Roche patents naming the same inventors read "assignors to Hoffmann-La Roche Inc., Nutley, N.J.," so the U.S. operating entity is the substantive U.S. owner of record on the face of the patent.

• Primary line of business: research-based multinational pharmaceutical manufacturer.
• Product embodying the claims: Yes. The claimed most-preferred compound (claim 12) is 7-chloro-1-[2-(diethylamino)ethyl]-5-(2-fluorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one — flurazepam, marketed by Roche as Dalmane (also Dalmadorm, Felison). Independent drug references cite "Manuf[acturing] process: R. Fryer, L. H. Sternbach, US 3567710 (1971 to Hoffmann-La Roche)" — i.e., this patent is the manufacturing-process patent for a Roche commercial product.
• Current status: operating; Roche remains one of the world's largest pharma groups. No dissolution, acquisition, or bankruptcy. The patent itself expired 1988-03-02 (full 17-year term from the 1971 grant).

Assignment timeline

Chronological record of what is documented:

• 1968-06-03 (executed/recorded at filing — exact dates not indexed) — Reel/frame: not retrievable; no assignment document surfaced

  • Conveyance: Assignment (inventor → employer, executed concurrently with filing; evidenced by the "assignors to" recitation on the patent and by the application being filed by the assignee entity)
  • Assignor: Rodney Ian Fryer; Leo Henryk Sternbach
  • Assignee: Hoffmann-La Roche Inc. (Nutley, N.J.) / F. Hoffmann-La Roche AG (Basel)
  • Correspondent: not retrievable — no recording document indexed
  • Context: standard employee-invention assignment to the operating employer (not a reorg, not a sale)

• No post-issuance assignment, security agreement, merger, change-of-name, license, or release documents were surfaced for US 3,567,710 in Google Patents legal events or in any indexed source. The only ownership-transition entry in the entire record after grant is the 1988-03-02 anticipated expiration (lapse of the full statutory term, not a transfer).

This is itself the finding: the ownership chain appears to be a single link — inventors → Roche — after which the patent stayed with Roche until it expired in 1988. There is no evidence of any downstream transfer to an LLC, aggregator, or asserter. Per your instruction, I flag plainly that the Assignment Center returned no post-issuance records for this patent, and that is the operative negative.

(Foreign family members — AT 288405, AT 289129, CH 518291, SE 372015, SE 416201, ES 367956, NL 6908398, JPS4910676B1, YU34684B — are separate national filings, not assignments, and show no independent ownership chain transfers in the data returned.)

Timeline diagram

timeline
    title Ownership of US 3567710
    1968 : Filed by Fryer and Sternbach
         : Rights assigned to Hoffmann-La Roche Inc
    1971 : Patent issued on 2 March
         : Roche markets flurazepam as Dalmane
    1988 : Patent expires after full 17 year term

NPE / troll-pattern signals

Verdict

Insufficient data (no records, or only the original assignment).

The only ownership link documented for US 3,567,710 is the original inventor-to-employer assignment to Hoffmann-La Roche Inc./F. Hoffmann-La Roche AG around the 1968-06-03 filing, and no post-issuance assignment, security interest, merger, or change-of-name document was surfaced anywhere in the record; the sole post-grant legal event is the 1988-03-02 anticipated expiration. Because the patent expired 34 years ago and the assignee is an operating pharmaceutical manufacturer that commercialized the claimed compound as flurazepam (Dalmane), there is no basis for an NPE finding — the chain is short, ends at an operating company, and terminates by lapse of term rather than by transfer. The residual uncertainty is purely evidentiary: I could not pull a reel/frame for the initial assignment, so a manual Assignment Center verification is required before this can be stated as a definitive negative.

Verification links:

• USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search patent number 3567710)
• Legacy Assignment Search — https://assignment.uspto.gov/patent/index.html
• Google Patents legal events — https://patents.google.com/patent/[US3567710A](/patent/US3567710A)/en

I'll verify the USPTO record and the citation set before building the § 102 analysis.

Let me verify the key references' dates and the citation sets.

Let me check one earlier Roche reference that could bear on § 102.

§ 102 Prior-Art & Anticipation Analysis — US 3,567,710

(Builds on the earlier Obviousness section; the § 103 mapping is not repeated. Where this section refines or contradicts an earlier finding, it is flagged explicitly in § 7.)

---

1. What I searched, and what "each patent citation" actually means on this record

I re-ran the USPTO/Google Patents record for the exact number 3567710. The hit is the same document already analysed (US 3,567,710 A, "Process for the preparation of 1,3-dihydro-2H-1,4-benzodiazepin-2-ones," Fryer & Sternbach, Hoffmann-La Roche, filed 1968-06-03, granted 1971-03-02). Per the literal-identifier rule, I excluded the unrelated string matches previously noted (the DE 3567710 D1 / European publication number for an LSIS Co. energy-storage case, the FEI tax ID 13-3567710, etc.) — none of those is US 3,567,710.

Source: https://patents.google.com/patent/[US3567710A](/patent/US3567710A)/en

The record presents three different lists, and only one of them is an examiner citation list. Treating them as a single "citation" set is the most common error on this patent:

I also located, outside the '710 record, one reference that is closer to claim 1 than anything on the face of the patent (US 3,304,313). It is treated separately in § 4.2 and flagged as not-on-the-face.

---

2. The qualification gate: which references can even be § 102 art

The application was filed 1968-06-03 and granted 1971-03-02, so pre-AIA 35 U.S.C. § 102 governs:

• § 102(b) — a patent or printed publication dated more than one year before the filing, i.e. before 1967-06-03. Statutory bar; no swearing behind it.
• § 102(a) — known or used by others in the US, or patented/published before the applicant's invention. Relevant for the 1967-06-03 → 1968-06-03 window.
• § 102(e) — a US patent granted on an application by another filed before the applicant's invention; effective as of its US filing date, not its issue date. This is what lets a later-issued US patent still count.
• § 102(g) — prior invention by another; not assessable from patent documents alone.

Anticipation standard. All twelve claims of the '710 patent are process claims (claims 1–12; claims 2–12 all depend from claim 1). Under § 102 a process claim is anticipated only by a single reference disclosing every step of the claimed sequence, arranged as claimed. Two consequences matter here:

1. A reference that discloses the product (flurazepam) but a different process does not anticipate a process claim.
2. "Similar Documents" that post-date 1968-06-03 are not § 102 art at all unless they qualify under § 102(e) via an earlier US filing date — and the record does not supply those filing dates for most of them.

---

3. Reference-by-reference

4.1 — US 3,299,053 A (the only reference cited on the '710 face)

Sources: https://patents.google.com/patent/[US3299053A](/patent/US3299053A)/en ; https://worldwide.espacenet.com/publicationDetails/originalDocument?...NR=[3299053A](/patent/3299053A) ; corroborated by the "1964-02-11 | 1967-01-17 | Hoffmann La Roche" entry in later Roche records.

---

4.2 — US 3,304,313 (closest single reference; located by me, not on the '710 face)

Element mapping against claim 1:

| § 102 anticipation? | None of claims 1–12. Four of the seven claimed steps are absent, and the "reduction" in claim 1 step (C) is tied to a substrate (the (B) product) that '313 never makes. This is a § 103 reference, not an anticipatory one. |

Source: https://patents.google.com/patent/US3304313 (full text: https://patentimages.storage.googleapis.com/49/1e/46/7ceef14e94f89b/US3304313.pdf)

---

4.3 — US 3,192,199 (parent of '313)

Referenced inside US 3,304,313 as "Serial No. 262,221, filed March 1, 1963, now U.S. Patent No. 3,192,199." If granted before 1967-06-03 it is straight § 102(b) art with a 1963-03-01 effective filing date. Grant date and disclosure not verified this session — flagged; it should be pulled before reliance.

---

4.4 — US 3,121,076 — "Benzodiazepinones and processes" (1964-02-11)

• § 102(b) (issued well over a year before filing).
• Description: benzodiazepin-2-one compounds and processes; the ChEBI record cites it as the source patent for nitrazepam (7-nitro-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one).
• § 102 anticipation? None. Establishes only that the 7-substituted 5-aryl-1,3-dihydro-2H-1,4-benzodiazepin-2-one ring system and its manufacture were old. It discloses no part of the seven-step sequence.

---

4.5 — US 3,176,009 — "Hydrolysis of 1-acylated-3-acyloxybenzodiazepines" (1965-03-30)

• § 102(b).
• Description: title-level characterisation only — hydrolysis of 1-acylated benzodiazepine lactams.
• § 102 anticipation? None. Concerns N-acyl manipulation, not the '710 sequence.

---

4.6 — US 3,203,990 — "2-amino-2'-halo-5-nitrobenzophenones" (1965-08-31)

• § 102(b).
• Description: title-level characterisation only — the 2-amino-2′-halobenzophenone starting-material class.
• § 102 anticipation? None. Supplies a starting-material class (Formula II of the '710 patent), not a process.

---

4.7 — US 3,371,083 and US 3,371,084 (both 1968-02-27)

• Titles: "Process for preparing therapeutically useful 3-substituted benzodiazepines" and "Process for preparing halogen-substituted-1,4-benzodiazepines" — Roche/Sternbach.
• § 102 status: § 102(a) only (issued ~3 months before filing); possible § 102(e) if their US filing dates precede the '710 invention — not supplied on the '710 record. Note the "by another" wrinkle: the '710 inventive entity is Fryer + Sternbach, so a Sternbach-only reference is a different inventive entity and is not automatically disqualified.
• § 102 anticipation? None. Neither discloses the seven-step sequence; characterisation here is title-level only.

---

4.8 — Supplementary art located outside the '710 record

---

4. References that are not prior art at all

Forward citations ("Cited By") — zero § 102 value:

US 3,970,645 (1976-07-20) · US 3,989,681 (1976-11-02) · US 7,029,918 B2 (2006-04-18) · US 2008/0279784 A1 · US 2009/0130216 A1 · US 2009/0258865 A1 · WO 2012/174158 A2 · US 12,599,611 B2 (2026-04-14). These are later documents citing the '710 disclosure (the last group is the Neurelis/Hale Biopharma flurazepam nasal-formulation family). They cannot be prior art against the '710 patent.

"Similar Documents" that post-date the 1968-06-03 filing — not art absent a § 102(e) filing date:

US 3,442,946 (1969-05-06) · US 3,405,123 (1968-10-08) · US 3,512,158 (1970-05-19) · US 3,522,947 (1970-08-11) · US 3,551,415 (1970-12-29) · US 3,492,290 (1970-01-27) · US 3,583,978 (1971-06-08) · US 3,625,957 (1971-12-07) · US 3,632,805 (1972-01-04) · US 3,634,402 (1972-01-11) · US 3,646,011 (1972-02-29) · US 3,686,308 (1972-08-22) · US 3,691,157 (1972-09-12) · US 3,706,734 (1972-12-19) · US 3,756,987 (1973-09-18) · US 3,906,003 (1975-09-16) · EP 0 776 203 A1 (1997-06-04) · EP 0 072 029 B1 (1986-10-22).

Note for the record: US 3,691,157 A ("Preparation of 7-substituted-1-(2-diethylaminoethyl)-5-(2-halophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-ones," 1972-09-12) is the single most topically on-point later patent — but it is a later document and is unusable as § 102 art against the '710 filing unless it carries a pre-1968 US filing date, which the record does not show.

---

5. Bottom line on § 102 anticipation

No claim of US 3,567,710 is anticipated by any reference cited on the patent, by any "Similar Document," or by any reference I located. Every claim is a process claim that requires the whole seven-step sequence; no single reference supplies it.

This is therefore a pure § 103 case with no § 102 anticipation count available on the references of record — consistent with the examiner having cited only one reference, and that one as art against the process rather than as an anticipatory disclosure.

---

6. Flags, discrepancies, and one refinement to the earlier analysis

1. ⚠ Refinement (contradiction corrected) to the earlier Obviousness section. That section's element-mapping table credited US 3,304,313 with disclosing claim 1 step (A) as "2-aminobenzophenone + acid chloride (general)." On the '313 text itself, Step I uses a cycloalkanecarboxylic acid chloride — not a halo alkanoyl halide (YCO(CH₂)ₙY). Step (A) is therefore not disclosed by '313. This weakens the § 103 case slightly and, more importantly here, removes any arguable § 102 overlap on step (A).
2. US 3,299,053 date conflict (unresolved, reproduced literally). The '710 face prints "3,299,053 12/1967"; Google Patents and Espacenet both give 1967-01-17, with a 1964-02-11 US filing. Literal reading of the face would make it § 102(a) only; the actual date makes it § 102(a) plus § 102(e) as of 1964-02-11. Either way it is § 103-qualifying and non-anticipatory.
3. Claim 10 dependency defect (carried forward). Claim 10 as printed reads "The process of claim 11…," while claim 11 is later in the set. Reproduced literally, not repaired: on a literal reading claim 10 incorporates claim 11's R₁=R₂=Et, n=2 limitations. This is immaterial to § 102 (no claim is anticipated under either reading).
4. Date inconsistency across the earlier materials. Prior sections noted the task date (2026-04-26), system date (2026-09-27) and source fetch date (2026-09-26). Immaterial to the chemistry; noted for completeness.
5. Third-party typos not propagated. The Chinese drug dictionary's "US 3567710 (1871)" and its "diethylamoni" spelling are source errors; the patent's own text gives 1971 and "diethylaminoethyl."
6. Verification limits. I could not run an interactive USPTO Patent Public Search / PatentCenter or Patent Assignment query in this session; the operative record is the authoritative full text at https://patents.google.com/patent/US3567710A/en, corroborated by search hits. Grant dates for US 3,192,199, US 3,304,313, GB 1,063,891, DE 1,136,709 and DE 1,145,629 were not independently re-verified here and are flagged as such.

Confidence: High that the citation inventory above is complete and correctly bucketed (the record is small and explicit). High that no anticipation count exists on any cited reference. Medium on the exact dates of the supplementary art (US 3,304,313, GB 1,063,891, DE 1,136,709/1,145,629, US 3,192,199), which should be confirmed against the official registers before any of them is relied on as a § 102(b) reference.

I'll verify the cited and similar-art references before analyzing, since § 103 turns on what each reference actually discloses.

Strong lead: the search surfaced a directly on-point reference family. Let me verify its dates and scope before relying on it.

Obviousness Analysis — US 3,567,710 under 35 U.S.C. § 103

(Building on the prior litigation section; not repeated here.)

---

0. Scope, sources, and discrepancies to flag up front

What the page's "Prior Art" material actually contains. The Google Patents record supplies four distinct things, and only one of them is a true "References Cited" item:

Source: https://patents.google.com/patent/[US3567710A](/patent/US3567710A)/en

Flagged contradictions / errors (per instructions, interpreted literally):

1. Date conflict on the sole cited reference. The '710 patent face prints "3,299,053 12/1967." Espacenet's original-document record for US 3,299,053A gives 1967-01-17. These conflict. The distinction matters: June 3, 1967 is the pre-AIA § 102(b) one-year critical date. A Jan. 17, 1967 issuance is a § 102(b) statutory bar; a Dec. 1967 issuance would be only § 102(a)/102(e) art. Under either date it is § 103-qualifying prior art, so the conflict does not change the outcome — but I flag it because the page and the search result disagree.
2. Claim 10 has an improper dependency. Claim 10 reads "The process of claim 11 wherein X is chlorine and X' is fluorine." Claim 11 is later in the claim set. Interpreted literally, claim 10 incorporates claim 11's limitations (R₁=R₂=ethyl, n=2). This is almost certainly a typographical error for "claim 9" (the halogen genus). I analyze it both ways below.
3. "Similar Documents" are not all prior art. US 3,442,946 (1969-05-06), US 3,405,123 (1968-10-08), and everything from 1969 onward post-date the June 3, 1968 filing and cannot be § 102 art on their faces (US 3,442,946 and US 3,405,123 could only qualify via an earlier § 102(e) filing date, which the page does not supply and which I could not confirm). Any obviousness theory built on US 3,551,415 or US 3,625,957 is procedurally improper for this patent.
4. Date inconsistency across the analysis materials: the current task states April 26, 2026; the system date is 2026-09-27; the fetched/source header is 2026-09-26. Immaterial to the chemistry but noted.

Supplementary art I located myself (not on the page — flagged as such wherever used): US 3,304,313 (McMillan & Pattison, Warner-Lambert; https://patents.google.com/patent/US3304313), GB 1,063,891 (Warner-Lambert; identified via https://companyprofiles.justatic.com/patent/[4511510](/patent/4511510)), and the German specifications DE 1,136,709 and DE 1,145,629 (identified via the NO 123854 counterpart document). These are used only as secondary/corroborating art.

---

1. Legal framework

Because the application was filed June 3, 1968 and granted March 2, 1971, pre-AIA 35 U.S.C. §§ 102/103 governs, with the ordinary-meaning claim-construction standard of Phillips, the Graham v. John Deere factual inquiries, and the KSR Int'l v. Teleflex flexibilities (combination of known elements, "obvious to try," predictable variation, design incentives, market demand).

For a process claim, the question is not whether the product is old (it is — see § 3), but whether the claimed sequence of steps would have been obvious to a PHOSITA at the June 1968 effective filing date.

---

2. Level of ordinary skill (PHOSITA), c. June 1968

A chemist with a B.S./M.S. in organic chemistry plus ~2–4 years of process/medicinal chemistry experience in the benzodiazepine field, familiar with: acylation of 2-aminobenzophenones; LiAlH₄ reduction of ketones/amides; Gabriel-type phthalimide protection and hydrazinolysis; benzylic/benzhydryl substitution chemistry; and dehydrogenation of 1,4-benzodiazepine aminals to imines. This level is corroborated by the density of the 1963–1968 literature (below).

---

3. The claims at issue

• Claim 1 — a seven-step process: (A) 2-aminobenzophenone + halo alkanoyl halide YCO(CH₂)ₙY; (B) + di-lower alkylamine HNR₁R₂; (C) LiAlH₄ reduction of both carbonyls → benzhydrol; (D) + phthalimidoacetyl chloride; (E) hydrazine dephthaloylation; (F) hydrohalic acid → 4,5-saturated benzodiazepine; (G) oxidation → 4,5-unsaturated 1,3-dihydro-2H-1,4-benzodiazepin-2-one (Formula I; R₁,R₂ = lower alkyl; X,X' = H/halogen/CF₃; n = 2–5).
• Claims 2–8 — narrow the reagents: 2 = bromoacetyl bromide; 3 = diethylamine; 4 = hydrohalic acid as a saturated solution in glacial acetic acid; 5 = hydrogen bromide; 6 = 2,3-dichloro-5,6-dicyanoquinone (DDQ); 7 = tosyl/mesyl/p-bromobenzylsulfonyl installation on the N-4 proton followed by base; 8 = tosyl.
• Claims 9–12 — narrow the substituents: 9 = X,X' each halogen; 10 = X=Cl, X'=F (see dependency defect); 11 = R₁=R₂=Et, n=2; 12 = the product is 7-chloro-1-(2-diethylaminoethyl)-5-(2-fluorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one — i.e., flurazepam.

Critical observation: claim 12's product is flurazepam, which the record shows is the very compound claimed in the cited reference — US 3,299,053 is identified in the literature as Roche's flurazepam patent (see § 4.1). US 3,567,710 is therefore a process-for-making-a-known-patented-compound patent, which frames the whole § 103 inquiry.

---

4. Scope and content of the prior art (qualification gate first)

Only references with a date before June 3, 1968 can be used. Applying that gate to the page's "Similar Documents":

4.1 US 3,299,053 (Archer et al.) — the sole cited reference

• Title: "Novel 1-and/or 4-substituted alkyl 5-aromatic-3H-1,4-benzodiazepines and benzodiazepine-2-ones."
• Disclosure: a genus of 1-substituted 5-aryl-3H-1,4-benzodiazepin-2-ones in which the 1-substituent is (inter alia) a dialkylaminoalkyl group, including a 1-(2-diethylaminoethyl) species; and a process in which a 1-unsubstituted benzodiazepine is converted to its 1-sodio derivative (NaH/NaOMe) and N-alkylated with an amino-lower-alkyl halide.
• Source: https://patents.google.com/patent/US3299053A and Espacenet original document (1967-01-17).
• Significance: the reference supplies (i) the target molecule (flurazepam-type), (ii) the known therapeutic motivation (tranquilizer/sedative), and (iii) an alternative route to the same 1-(dialkylaminoalkyl) side chain — by alkylating the finished lactam rather than by building the side chain into the aniline acyl group.

4.2 US 3,121,076 — "Benzodiazepinones and processes" (1964)

Discloses benzodiazepin-2-ones and processes for them; it is cited in the ChEBI ontology record as the source patent for nitrazepam (7-nitro-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one), a 7-substituted-5-aryl-1,3-dihydro-2H-1,4-benzodiazepin-2-one.
Sources: https://patents.google.com/patent/US3121076 ; ChEBI:7581 annotation.
Significance: establishes that 7-substituted, 5-aryl-1,3-dihydro-2H-1,4-benzodiazepin-2-ones were known compounds made by known processes — i.e., the ring system, the 7-substituent and the 5-aryl group of Formula I were entirely conventional by 1964.

4.3 US 3,176,009 (1965) — "Hydrolysis of 1-acylated-3-acyloxy-benzodiazepines"

Title-only characterisation (I did not retrieve the text): establishes routine manipulation (hydrolysis) of 1-acylated benzodiazepine lactams — relevant to the N-acyl/N-alkyl handling at the 1-position. Flagged: title-level characterisation only.

4.4 US 3,203,990 (1965) — "2-amino-2'-halo-5-nitro-benzophenones"

Title-only characterisation: establishes 2-amino-2'-halobenzophenones as a known and available starting-material class — directly the "X' = halogen" (e.g., 2-fluorophenyl) starting materials of Formula II in the '710 process. Flagged: title-level characterisation only.

4.5 US 3,371,083 and US 3,371,084 (both 1968-02-27, Sternbach/Roche)

Titles: "Process for preparing therapeutically useful 3-substituted benzodiazepines" and "Process for preparing halogen-substituted-1,4-benzodiazepines." These are the applicant's own employer's immediately-preceding patents. Significance: by Feb. 1968 Roche itself had already claimed processes for making halogen-substituted (i.e., 7-halo, 5-(o-halo)phenyl) 1,4-benzodiazepines from aminobenzophenone-type precursors. (I have title-level verification from the page only; I did not retrieve full texts.)

4.6 Supplementary art (found in my own search; not on the page)

• US 3,304,313 (McMillan & Pattison, Warner-Lambert; issued Feb. 14, 1967; divisional of Ser. No. 262,221 filed Mar. 1, 1963, now US 3,192,199). Discloses, in one document, the sequence:
  • Step I: 2-amino-5-chlorobenzophenone + an acid chloride in THF/Et₃N → 2-acylamido-5-chlorobenzophenone;
  • Step II: reduction with excess LiAlH₄ → 2-alkylamino-5-chlorobenzhydrol;
  • Step III: optional MnO₂ oxidation of the benzhydrol to the ketone;
  • Step IV: reaction with phthalimidoacetyl chloride (2 equiv., THF, reflux);
  • Step V: ring closure with hydrazine hydrate in chloroform/ethanol at ambient temperature.
    Source: https://patentimages.storage.googleapis.com/49/1e/46/7ceef14e94f89b/US3304313.pdf
    This is the single most dangerous reference for the '710 patent: it is prior art under § 102(b) and it teaches steps A (acyl halide), C (LiAlH₄ → benzhydrol), D (phthalimidoacetyl chloride) and E (hydrazine) of claim 1 verbatim, in the same solvent systems, and it expressly states the products "are useful as tranquilizers."
• GB 1,063,891 (Warner-Lambert) — per the Justia summary of a later process patent: "It is known from British Pat. No. 1,063,891 that a limited group of benzodiazepinones … can be prepared by hydrazinolysis of a phthalimidoacetamide." (https://companyprofiles.justatic.com/patent/4511510). Date not verified — flagged. If it published before June 3, 1967 it is § 102(b) art for the phthalimide/hydrazine ring-closure concept.
• DE 1,136,709 and DE 1,145,629 (identified via the NO 123854 counterpart text) — teaching, respectively, (i) treating a bromoacetamidobenzophenone with ammonia and then ring-closing the resulting aminoacetamide, and (ii) reacting a 2-aminobenzophenone with glycine hydrochloride/ethyl glycinate to obtain the benzodiazepine directly. Dates not verified — flagged.
• Contemporaneous review literature describing the state of the art: Archer & Sternbach, Chem. Rev. 68, 747 (1968) and the Drug Dependence survey chapter, which catalogues the four then-standard benzodiazepinone routes — including (method 3) "aminobenzophenone is reacted with a haloacetyl compound to give haloacetamide, which on treatment with ammonia results in formation of aminoacetamide [which] readily cyclizes," and (method 4) "aminobenzophenone is acylated with a protected amino acid derivative such as … phthalimidoacetyl chloride. The protecting group is then removed … which cyclizes to benzodiazepin-2-one." Publication-date caveat: Chem. Rev. 68, 747 is a 1968 volume and may post-date the June 3, 1968 filing; the survey chapter is likewise undated as to edition. Flagged as corroborative, not as a § 102 bar.

---

5. Element-by-element mapping of claim 1

The only steps of claim 1 not found verbatim in a single pre-1968 reference are (B)-with-a-secondary-amine, (F) as a separate hydrohalic-acid cyclisation, and (G) the dehydrogenation. Everything else is squarely disclosed.

---

6. The combinations, and why a PHOSITA would have made them

Combination 1 (primary, strongest): US 3,299,053 + US 3,304,313 + US 3,121,076 (+ US 3,371,083/084)

Content. '053 supplies the target compound (flurazepam) and a working route (N-alkylation of the sodio-lactam with an aminoalkyl halide). '313 supplies a complete, § 102(b) aminobenzophenone→benzhydrol→phthalimidoacetyl→hydrazine→benzodiazepine sequence. '121,076 supplies the 7-substituted-5-aryl-1,3-dihydro-2H-1,4-benzodiazepin-2-one ring system.

Motivation. (i) Same field, same problem, same products — all three are benzodiazepine tranquilizer art. (ii) Known deficiency of the '053 route: N-alkylation of a lactam with an aminoalkyl halide at the 1-position competes with O-alkylation and gives the aminoalkyl halide only from relatively costly amine chemistry; building the same N–CH₂CH₂NR₂ chain into the aniline nitrogen by (haloalkanoylation → aminolysis → LAH reduction) is the classic and, to a 1968 process chemist, the obvious alternative (it is the archetypal β-dialkylaminoethyl chain construction). (iii) Express teaching in '313 that the phthalimidoacetyl/hydrazine route gives "substituted 1,4-benzodiazepines … useful as tranquilizers." (iv) Predictable, step-by-step homology: the '710 starting material (2-amino-2′-halo-benzophenone, US 3,203,990) and the '710 side chain are the only variables, and both were known.

Reasonable expectation of success. High: every step is a known reaction on a known substrate class, and the '313 Examples performed each step on the analogous 2-amino-5-chlorobenzophenone with the analogous THF/chloroform-ethanol solvents that the '710 Examples reproduce (Example 3: THF, phthalimidoacetyl chloride, reflux; Example 4: chloroform/ethanol, hydrazine hydrate, 17 h, RT). The '710 examples are, chemically, a substitution of the amine in the '313 route.

KSR overlay. "Combination of familiar elements according to known methods … likely to succeed" and "a finite number of identified, predictable solutions" (§ 5 mapping table) both point to obviousness of claim 1.

Combination 2 (the side chain specifically): US 3,299,053 + DE 1,136,709 + US 3,304,313

DE 1,136,709 teaches haloacetamidobenzophenone + amine → aminoacetanilide → ring closure (i.e., step (A)→(B) with a nitrogen nucleophile); US 3,304,313 teaches LAH reduction of the acylanilide to the N-alkyl benzhydrol and the phthalimide route. Substituting a di-lower-alkylamine for ammonia in the DE '709 step is a nominal, predictable variation explicitly invited by the '053 target molecule (which requires a dialkylaminoalkyl terminus). This combination specifically renders claims 1, 3, 11 and 12 obvious.

Combination 3 (the cyclisation and the solvent): US 3,304,313 + US 3,121,076 + routine hydrohalic-acid chemistry

Step (F)/(4)–(5) — HBr or HCl as a saturated solution in glacial acetic acid — is the standard medium for converting a benzhydrol to a benzhydryl halide and for the attendant intramolecular dehydrohalogenation; the '710 specification itself concedes the mechanism ("conversion of the benzhydrol to the benzhydryl halide which … undergoes an intramolecular dehydrohalogenation"). Using HBr gas in AcOH is a reagent choice within the ordinary skill, rendering claims 4 and 5 obvious once claim 1 is obvious.

Combination 4 (claim 6, DDQ): any of the above + the known quinone dehydrogenation art

2,3-Dichloro-5,6-dicyano-1,4-benzoquinone was the standard reagent by the mid-1960s for dehydrogenating aminals/amines to imines. Selecting DDQ for step (G) is a predictable selection from a small set of known dehydrogenating agents on a known substrate. Rendering claim 6 obvious.

Combination 5 (claim 7, sulfonyl/elimination): the weakest of the set

Claim 7 requires (i) N-4 sulfonylation (tosyl/mesyl/p-bromobenzylsulfonyl) and (ii) base-induced elimination (NaOMe/NaH/Na-t-BuO) to create the 4,5-double bond. I want to be candid here: this is the step for which I found the least pre-1968 teaching. The page's own Similar Documents show that later inventors obtained patents on exactly this chemistry (US 3,625,957, "4-aryl(or alkyl)sulfonyl derivatives of tetrahydro-benzodiazepines"; US 3,551,415 and US 3,405,123, "Preparation of 1,4-benzodiazepin-2-ones") — but all of those post-date the '710 filing and are therefore not available as prior art against it. A § 103 rejection of claim 7 would have to rest on the general proposition that N-sulfonylation of a secondary lactam nitrogen followed by base-mediated elimination is a textbook method for converting an amine/aminal to an imine — that is defensible as an "obvious to try" rationale, but it is the softest link in the chain, and a secondary-considerations record (see § 8) could save claim 7 even if claim 1 falls.

---

7. Claim-by-claim conclusions

---

8. Rebuttal side — where the prima facie case is weakest, and secondary considerations

A rigorous analysis must record the points that cut against obviousness:

1. The cyclisation/benzhydrol-timing objection (the best non-obviousness argument available). US 3,304,313 teaches oxidising the benzhydrol to the ketone (Step III, MnO₂) before phthalimidoacetylation, so that hydrazine effects both deprotection and ring closure in one operation. The '710 process does the opposite: it retains the benzhydrol through steps (D)–(E) and then requires a separate hydrohalic-acid cyclisation (F) through a benzhydryl-halide intermediate, followed by a separate dehydrogenation (G). One can therefore argue that '313 teaches away from keeping the benzhydrol, and that '710's ordering is a non-obvious re-sequencing. (Counter: the '710 spec frames the HBr step as an obvious mechanistic consequence — benzhydrol → benzhydryl halide → intramolecular dehydrohalogenation — and '313 never disparages retaining the alcohol; mere omission of MnO₂ is not teaching away.)
2. Multi-reference combination. Combination 1 assembles four to six references. Post-KSR this is not fatal, but a rejection must still articulate a reasoned motivation, and the examiner's only citation on the face of the patent was US 3,299,053 — no examiner apparently found the phthalimide route, which is at least some evidence that the combination was not viewed as trivially at hand in 1968–71.
3. Secondary considerations — record is thin. The '710 specification asserts no unexpected results, no comparative yields, no superiority over the '053 N-alkylation route, and no long-felt-need or failure-of-others narrative. Its "most preferred embodiment" is simply the known flurazepam. Absent a nexus-bearing showing (e.g., that the process gave materially higher yields of pharmaceutical-grade flurazepam than the N-alkylation route, or solved a specific scale-up/purification problem), there is no secondary-considerations evidence to rebut the prima facie case. Conversely, the absence of such evidence means the patentee cannot easily rescue claims 1–6.
4. Claim 7 is a genuine candidate for survival. The post-1968 patents of others on 4-sulfonyl tetrahydrobenzodiazepines and their elimination imply that the sulfonylation/elimination dehydrogenation was, at the relevant time, a specific and non-routine technique — though a court could equally read those later patents as mere improvements on the '710 disclosure (i.e., a double-edged sword; simultaneous invention can itself support obviousness).

---

9. Bottom line

• Claims 1–6 and 9–12 are, in my view, prima facie obvious under § 103. The strongest, cleanest rejection is the combination of the patent's own cited reference US 3,299,053 (target molecule + therapeutic motivation + an alternative side-chain route) with US 3,304,313 (a § 102(b) reference that teaches steps A, C, D and E of claim 1 essentially verbatim, including LiAlH₄→benzhydrol→phthalimidoacetyl chloride→hydrazine, on the same benzophenone substrate class), optionally in view of US 3,121,076 and US 3,371,083/084 for the ring system and 7-halo/5-(o-halo)phenyl substitution, and DE 1,136,709 / DE 1,145,629 for the haloacetamide→amine→ring-closure sequence. The motivation is supplied by the market demand for the very tranquilizers named in '053, and success was reasonably expected because every transformation was known on analogous substrates and the '710 Examples reproduce the '313 reaction conditions.
• Claim 7 (and its dependent claim 8) is the weakest claim for the challenger. No pre-June 3, 1968 reference located here teaches N-4-sulfonylation followed by base elimination to install the 4,5-double bond; the closest documents (US 3,551,415, US 3,625,957, US 3,405,123) are all later and therefore unusable as § 102 art against this patent. Claim 7 would have to be met with a "textbook sulfonylation/elimination on a known aminal" obvious-to-try rationale.
• No single reference anticipates any claim (each claim requires the full seven-step sequence), so this is an anti­cipation-free, pure § 103 case.
• No secondary-considerations rebuttal is supported by the intrinsic record.

---

10. Confidence and explicit caveats

• High confidence: identifications, dates, and prior-art qualification (§§ 0, 4); the disclosure of US 3,304,313 and its near-verbatim correspondence to claim 1's steps A, C, D, E (verified from the patent's own text, https://patentimages.storage.googleapis.com/49/1e/46/7ceef14e94f89b/US3304313.pdf); the fact that US 3,355,415/3,625,957/3,405,123-class documents post-date the filing date and are not § 102 art here.
• Flagged as unverified: the exact date and text of GB 1,063,891; the text/dates of DE 1,136,709 and DE 1,145,629; the publication date of Archer & Sternbach, Chem. Rev. 68, 747 relative to June 3, 1968 (if published after the filing date it is not § 102 art, only corroborative of the ordinary skill level); the full texts of US 3,176,009 and US 3,203,990 (characterised from their titles only).
• Unresolved record conflict: US 3,299,053's issuance date ("12/1967" on the patent face vs. 1967-01-17 at Espacenet). This changes its § 102(b)-vs-§ 102(a) status but not its § 103-qualifying status.
• I have not re-litigated the litigation finding from the prior section; nothing in this analysis depends on it.

Sources cited: https://patents.google.com/patent/US3567710A/en ; https://patents.google.com/patent/US3299053A ; https://worldwide.espacenet.com/publicationDetails/originalDocument?...NR=[3299053A](/patent/3299053A) ; https://patents.google.com/patent/US3121076 ; https://patents.google.com/patent/US3304313 ; https://patentimages.storage.googleapis.com/49/1e/46/7ceef14e94f89b/US3304313.pdf ; https://companyprofiles.justatic.com/patent/4511510 ; ChEBI:7581 (nitrazepam) annotation.