US 4458066

I'll verify the patent details and check for any litigation/docket information before summarizing.

Let me try to locate the actual claim text and check for any 2026 appellate activity.

Let me attempt to retrieve the full claim set and check for any recent (2026) appellate activity.

Verification status first

I was able to corroborate the bibliographic data for US 4,458,066 across the authoritative Google Patents text supplied to me plus Espacenet and uspto.report search results. I could not retrieve the patent's full printed claim set, and I found no 2026 CAFC docket activity. Both gaps are flagged below rather than filled in by inference.

Bibliographic summary — US 4,458,066

Note on the "prior art date 1980‑02‑29" appearing on the Google Patents page: that is the parent‑application priority date, not the '066 filing date. Several third‑party databases (e.g., citation listings on Google Patents family pages) show "US4458066A | 1980‑02‑29 | 1984‑07‑03," which reflects priority rather than filing.

Abstract (verbatim)

"New and useful intermediate nucleotides bound to an inorganic polymer support, including the preparation thereof, and processes for the conversion to oligonucleotides which are especially useful for the synthesis of polynucleotides, particularly ribonucleic (RNA) and deoxyribonucleic acids (DNA)."

Overview of the claimed subject matter

Important limitation on this section: the claim set was not present in the patent text available to me (the fetched description truncates mid‑sentence), and my searches did not surface the printed claims from an authoritative source. What follows is a plain‑language account of the claimed subject matter as described in the specification and as reported in secondary sources, with the source and confidence level noted. I am not able to confirm the exact number of claims, the precise number of independent claims, or the verbatim wording beyond claim 1.

Claim 1 as reported in a secondary source (BLR 389, reproducing the "principal claims" of US 4,415,732 and US 4,458,066) reads substantially: "A modified inorganic polymer represented by the formula: … wherein ○ is an inorganic polymer linked to the 3'‑ or 5'‑O‑ of the nucleoside through a base hydrolyzable covalent bond; R is H or a blocking group; R₁ is a hydrocarbon radical containing up to 10 carbons; each B is a nucleoside or deoxynucleoside base; and each A is H or OR." Confidence: moderate — the text is quoted from a secondary reproduction, not the patent itself.

In plain language, that composition claim covers:

1. A modified inorganic support — an inorganic polymer (silica gel preferred; silica, porous glass, aluminosilicates, borosilicates, metal oxides such as alumina and nickel oxide, and clays are all named) that is chemically bound to a nucleoside or a short oligonucleotide.
2. Attachment through a base‑hydrolyzable covalent bond at the nucleoside's 3'‑ or 5'‑O‑ position. This is the patent's central structural point: the linker must survive the synthesis cycles but be cleavable at the end with a weak base such as ammonium hydroxide (ester linkages from succinic/glutaric/adipic/phthalic/maleic diacids, or amide linkages, are taught).
3. A hydroxymethyl/phosphate‑bearing sugar — R is H or a blocking group (trityl, methoxytrityl, dimethoxytrityl, dialkylphosphite, t‑butyldimethylsilyl, etc.); A is H or OR, which is how the claim reaches both deoxyribonucleosides (A = H) and ribonucleosides (A = OR).
4. Any nucleoside base B — the claim is not limited to pyrimidines, which is the stated advance over the prior art (Köster, Tetrahedron Letters 1527‑1530, 1972), whose trityl attachment was reportedly limited to pyrimidine nucleosides and required acid cleavage to which purines are sensitive.

Process claims. The specification describes and the patent appears to claim process subject matter directed to the stepwise solid‑phase route: (a) condensing the free 3'‑ or 5'‑OH of the support‑bound nucleoside/oligonucleotide with a nucleoside bearing a phosphite linking group (e.g., a nucleoside methylphosphomonochloridite or its tetrazolide/nitroimidazolide/triazolide), (b) capping unreacted hydroxyls, (c) oxidizing the phosphite triester to a phosphate, and (d) removing the blocking group to regenerate a reactive hydroxyl — repeating (a)–(d) until the desired sequence is obtained, then hydrolyzing the oligonucleotide off the support. The specification also emphasizes a Lewis‑acid detritylation step (zinc bromide preferred; TiCl₄, BF₃, AlCl₃ alternatives) that avoids depurination. I cannot confirm from the sources available to me which of these are independent claims, whether claim 1 is the sole composition claim, or the total claim count.

Historical note on claim scope (from litigation records, not the patent's face): In the Affymetrix v. PE Corp. record, the EPO counterpart's claims "1‑24, 27, 29 and 30" are described as identical in numbering and content to the claims that issued in the '066 patent, and during prosecution the examiner allowed claims 18‑42 of the '066 application — suggesting the '066 patent carries on the order of 40+ claims with multiple independents. This is consistent with, but does not prove, that structure.

Litigation / docket check (relevant to the "CAFC 2026" request)

• No 2026 CAFC docket or 2026 appellate activity for US 4,458,066 was found. I cannot rule out that such a docket exists in a database I did not reach; treat this as "not found," not as "confirmed none."
• The Google Patents page lists two litigation links: N.D. Cal. case 3:97‑cv‑00118 and D. Del. case 1:00‑cv‑00629, plus a Darts‑IP "first worldwide family litigation" pointer.
• Historical matters involving this patent family that surfaced in searching: Millipore Corp. v. University Patents, Inc. (declaratory judgment over the '066 family); Affymetrix, Inc. v. PE Corp. (inequitable conduct allegations concerning nondisclosure of UPI's February 1980 Tetrahedron Letters article — the same article the EPO cited in a Nov. 12, 1983 notice of deficiency against counterpart claims 1‑24, 27, 29, 30); and BPAI Interference No. 101,724, Itakura v. Caruthers (final decision June 11, 1991), in which Itakura conceded priority as to claims 1‑44 of US 4,373,071 and judgment was entered against Itakura. That interference expressly noted the involved Caruthers application (Ser. No. 06/601,813) was accorded benefit of Ser. No. 06/247,144, "now Patent No. 4,458,066."
• Enforcement relevance: the '066 patent expired (anticipated expiration July 3, 2001), so any 2026 appellate activity would concern collateral matters (e.g., later‑filed patents claiming benefit, or contract/licensing disputes over "Related Patent" definitions) rather than live infringement of the '066 claims.

Explicit uncertainties

1. Claim text and claim count — not verified against the patent's printed claims. The claim 1 wording above comes from a secondary reproduction of "principal claims" and should be confirmed against the USPTO PatentCenter full‑text document before being quoted as authoritative.
2. Assignee chain — Google Patents shows "University Patents, Inc." as current assignee and disclaims accuracy of assignee listings; no 2026 reassignment was verified. (A March 18, 1983 assignment record to University Patents, Inc. from Matteucci and Caruthers appears in the prosecution history.)
3. Government rights — the only statement available is the specification's reference to a Department of Health, Education and Welfare grant/award; the specific grant number was not in the text I received.
4. No 2026 CAFC docket found — absence of evidence here is not evidence of absence.

I'll research litigation involving US patent 4458066. Let me start with the litigation data sources and the patent's own record.

Let me dig into the specific litigation records referenced on the patent's Google Patents page and related cases.

Let me search for the specific case numbers and the parties involved.

I hit the search-step limit, so this answer reflects the sources I was able to retrieve plus the patent's own authoritative text. I've deliberately flagged items I could not verify rather than filling gaps by inference.

Litigation involving US 4,458,066

Bottom line

US 4,458,066 ("Process for preparing polynucleotides," Caruthers & Matteucci, filed 1981‑03‑24 as a CIP of Ser. No. 126,025 filed 1980‑02‑29, issued 1984‑07‑03, assignee University Patents, Inc., expired 2001‑07‑03) is not a patent with no known litigation. There is a small, well-identified cluster of activity, but the surviving records are thin and the two case numbers listed on Google Patents are given without party names, so I cannot confirm plaintiffs/defendants for those two entries.

1. The two litigation records on the patent's own face (Google Patents)

Source: https://patents.google.com/patent/US4458066/en — under "Family has litigation / First worldwide family litigation filed":

Important caveat: Google Patents attaches the family-level litigation list to every member of the family (the page also cross-links US 4,500,707, US 5,132,418 and US 5,153,319). I therefore cannot confirm that either case specifically asserted 4,458,066 — only that the Darts‑IP/Unified Patents harvest associated them with this family. The Unified Patents deep links are:

• https://portal.unifiedpatents.com/litigation/California%20Northern%20District%20Court/case/3%3A97-cv-00118
• https://portal.unifiedpatents.com/litigation/Delaware%20District%20Court/case/1%3A00-cv-00629

2. Affymetrix, Inc. v. PE Corporation (N.Y.) et al. — the substantive case

This is the case in which 4,458,066 was actually litigated on the merits.

• Plaintiff: Affymetrix, Inc.
• Defendants: PE Corporation (N.Y.); Competitive Technologies, Inc. (successor to University Patents, Inc.); Applera Corporation; Perseptive Biosystems, Inc.
• Jurisdiction: U.S. District Court — opinion retrieved via CourtListener (opinion id 2526031); the companion reports describe a parallel affirmative suit in the District of Delaware (see §3).
• Patents at issue: US 4,458,066; 4,500,707; 5,132,418; 5,153,319; and 4,973,679 (the Beaucage/Caruthers phosphoramidite line).
• Filing date: Not confirmed from the sources retrieved.
• Claims/outcome: Affymetrix sought a declaration of unenforceability for inequitable conduct, alleging that UPI/Competitive Technologies failed to disclose the Caruthers & Matteucci 1980 Tetrahedron Letters article "The Synthesis of Oligodeoxypyrimidines on a Polymer Support" (published 1980‑02‑19) to the examiner during prosecution of the '066 and '679 patents. The court denied defendants' Rule 12(b)(6) motion to dismiss that claim, holding that (i) it would require looking beyond the pleadings, and (ii) disclosure during an interference is not, as a matter of law, equivalent to disclosure to the Primary Examiner (A.B. Dick Co. v. Burroughs Corp., 798 F.2d 1392 (Fed. Cir. 1986)). The court also allowed a patent misuse theory concerning the '679 patent (enforcement past expiry due to the PTO's failure to print a terminal disclaimer).
• Current status: The patent expired 2001‑07‑03, so no live relief is available on the '066 patent today.
• Sources: https://www.courtlistener.com/opinion/2526031/affymetrix-inc-v-pe-corp/ ; http://g.casetext.com/case/affymetrix-inc-v-pe-corp-ny ; https://storage.courtlistener.com/harvard_pdf/[2447770](/patent/2447770).pdf

3. PE Biosystems v. Affymetrix (District of Delaware)

A BioCentury item reports that PEB (the Perkin‑Elmer/Applera side) sued Affymetrix in the U.S. District Court for the District of Delaware, alleging infringement of US 4,458,066; 4,500,707; 5,132,418; 5,153,319; and 4,973,679 — i.e., the mirror-image infringement action to Affymetrix's declaratory case.

• Source: https://www.biocentury.com/article/[189833](/patent/189833)/affymetrix-pe-biosystems-enabling-technology-news
• Case number: not confirmed. I was not able to verify whether this is Delaware 1:00-cv-00629 (the docket listed on Google Patents). Given the 2000 docket year and the parties, that identification is plausible but unverified — treat it as a lead, not a fact.
• Outcome/status: not confirmed from the sources retrieved.

4. Related proceedings that are not litigation (do not cite as cases)

• Ogilvie interference, 1982–1983. Dr. Kelvin K. Ogilvie declared an interference over the broadly worded count "A process for producing polynucleotides which comprises the step of condensing the 3′-OH or 5′-OH of a nucleoside linked to a functionalized inorganic polymer with a compound which is the reactive product of a nucleoside and a blocked phosphodichloridite." Ogilvie abandoned the interference five days after UPI moved to dissolve it. This is a PTO administrative priority contest, not court litigation, though the '066 application is the subject.
• EPO prosecution. UPI's parallel EP application (filed 1981‑02‑27) was attacked by a third party's letter (1983‑03‑25); the EPO's 1983‑11‑12 notice of deficiency stated the 1980 article destroyed novelty of claims 1–24, 27, 29 and 30 — claims identical in numbering and content to those that issued in the '066 patent.
• The Affymetrix opinion also notes that during the 1980s "UPI was in litigation with other parties who were alleging" the patents were invalid/unenforceable. Those additional 1980s cases are not identified in the sources I retrieved, and I will not guess at party names.

5. Items that are not litigation over this patent (guard against false positives)

The following surfaced in searches for the number but are unrelated to litigation involving 4,458,066:

• Nippon Shinyaku, Ltd. v. Sarepta Therapeutics, Inc., D. Del., 1:21-cv-01015-JLH (CourtListener docket 60054792, Doc. 508‑1). Here "4458066 / 1984-07-03 / Caruthers et al." appears only in an exhibits list of prior art, i.e., 4,458,066 cited as a reference against someone else's patent. Not a case about 4,458,066.
• Numerous EPO/JP specifications (EP 3222290 A1, EP 1951888 B1, EP 2173760 B1, EP 4008783 A1, HUP0401860A2, etc.) cite "US 4458066 A" as background art. Citation ≠ litigation.
• Justia "References Cited"/patent-family tables (e.g., US 5,565,555; US 10,517,889; US 12,533,422) likewise merely list 4,458,066 as prior art.

6. Confidence and gaps

• Moderate-to-high confidence: that 4,458,066 was asserted and litigated in the Affymetrix / PE Corporation–Competitive Technologies–Applera–Perseptive dispute, with the inequitable-conduct and misuse rulings as described, and that PEB filed a Delaware infringement suit naming the '066 patent.
• Low confidence / unverified: (a) the parties and filing dates for Cal. N.D. 3:97-cv-00118 and D. Del. 1:00-cv-00629; (b) whether the BioCentury-reported Delaware PEB suit is 1:00-cv-00629; (c) the final dispositions of either docket; (d) the identity of the unidentified 1980s suits referenced in the Affymetrix opinion; (e) any CAFC appeal outcome (I did not retrieve a Federal Circuit opinion and will not assert one exists).
• What would close these gaps: the Darts‑IP family record (https://patents.darts-ip.com/?family=26824202), PACER dockets for the two case numbers, and the full D. Del. docket for the PEB v. Affymetrix action.

I was unable to complete the additional verification searches I intended (per‑case‑number lookups and the CAFC/PACER docket pulls) because I reached the tool-step limit. The two case numbers on the patent's own record should be confirmed against PACER before being relied on in any filing.

I'll verify the structured data against public sources before writing anything.

PTAB / AIA Trial Landscape — US 4,458,066 ("Process for preparing polynucleotides")

Patent snapshot (from the authoritative full text): Caruthers & Matteucci; filed 1981-03-24 as a continuation‑in‑part of Ser. No. 126,025 (1980-02-29); granted 1984-07-03; original assignee University Patents Inc.; anticipated expiration 2001-07-03; legal status "Expired – Lifetime." Application No. US06/247,144.

Proceedings overview

There are zero AIA trial proceedings on file against US 4,458,066 — no IPR, no PGR, no CBM — and there could not have been any, because the patent expired on 2001-07-03, more than eleven years before the first IPR was even filable; the defensive bottom line is not "the patent survived IPRs" but "the patent is a dead letter — it expired in 2001, and its two most-used claim groups (claims 1‑13 and 18‑43) were held invalid under § 102(b) by a federal district court in 2004, so any demand letter citing them is baseless."

Nothing is active, nothing was instituted, nothing was settled. The absence of PTAB activity here is not the usual "well-asserted patents eventually attract IPRs" signal — it is a structural artifact of the patent's age.

No proceedings to list

The structured "PTAB proceedings on file" block returns no AIA trial proceedings from the USPTO Open Data Portal, and web search turned up no IPR, PGR, or CBM petition naming U.S. Patent No. 4,458,066 — not in the PTAB docket aggregation, not in the Google Patents "Family has litigation" entries (which list only district court cases, see below), and not in any defensive-aggregator activity I could locate. I am not fabricating a proceeding number to fill this section.

Why zero is the correct answer, not a data gap:

• IPR became available for petitions filed on/after 2012-09-16. This patent expired 2001-07-03. There is no live patent to review.
• PGR applies only to patents with an effective filing date on/after 2013-03-16 (AIA § 3(n)(1)). The '066 patent's effective filing date is 1980-02-29 / 1981-03-24.
• CBM requires a "covered business method" patent (a financial-services patent). This is an oligonucleotide-synthesis chemistry patent — categorically outside CBM eligibility, and in any event the CBM program sunset on 2020-09-16.

Non-AIA activity you should know about (context only — not PTAB AIA trials)

Because a defendant's real exposure here comes from district court history, not the Board, here is the relevant record. These are not AIA proceedings and are not in the structured proceedings list.

Pre-AIA interference — Ogilvie v. University Patents, Inc. (USPTO Board of Patent Appeals and Interferences)

• Type: Interference (pre-AIA 35 U.S.C. § 135), declared 1982-09-17 over the count: "A process for producing polynucleotides which comprises the step of condensing the 3'-OH or 5'-OH of a nucleoside linked to a functionalized inorganic polymer with a compound which is the reactive product of a nucleoside and a blocked phosphodichloridite."
• Outcome: On 1983-04-07 UPI moved to dissolve the interference, attaching the 1980 Tetrahedron Letters article and stating it "meets every material element and limitation of [the interference count]." Ogilvie abandoned the interference five days later; UPI withdrew its motion and the interference was terminated.
• Source: recited in Affymetrix, Inc. v. PE Corp., 306 F. Supp. 2d 363 (S.D.N.Y. 2004) — https://www.courtlistener.com/opinion/[2526031](/patent/2526031)/affymetrix-inc-v-pe-corp/
• Defensive value: This is the origin of the inequitable-conduct cloud over the Caruthers/UPI family — UPI used the article offensively in the interference and then failed to put it squarely before the prosecuting examiner.

Affymetrix, Inc. v. PE Corp., 306 F. Supp. 2d 363 (S.D.N.Y. 2004) (Judge Buchwald) — claims of '066 held invalid

• Type: District court declaratory judgment action (not a PTAB proceeding). Filed January 2001 in S.D.N.Y. after the Delaware action was dismissed; the D. Del. case (1:00-cv-00629) was dismissed 2001-09-27 for lack of subject matter jurisdiction. An earlier N.D. Cal. case (3:97-cv-00118) also appears in the litigation family.
• Disposition (2004-01-28): Summary judgment granted for Affymetrix that certain claims are anticipated under 35 U.S.C. § 102(b) by the Caruthers & Matteucci article, "The Synthesis of Oligodeoxypyrimidines on a Polymer Support," Tetrahedron Letters (published 1980-02-19). The court held:

  "we hold that claims 1-13 and 18-43 of the '066 patent and claims 1-7 and 21-24 of the '418 patents are invalid."

• Reasoning: The '066 patent is a CIP filed 1981-03-24, more than one year after the 1980 article. The CIP's broadened "inorganic polymer" support language and broadened "hydrocarbyl" phosphate-protecting-group language were not supported by the parent application under § 112 ¶ 1, so those claims got no benefit of the 1980-02-29 parent date and were barred by § 102(b). The court refused to let the inventors claim a genus after disclosing only a single species (silica gel; methyl).
• Not decided: The court denied summary judgment on inequitable conduct (genuine issue of material fact as to good-faith reliance on the 1982 interference priority determination) and denied the § 101/§ 112 challenge to the '679 patent. I could not confirm, from the sources available to me, the ultimate trial outcome on inequitable conduct or whether the invalidity ruling was appealed to the Federal Circuit — I won't guess at that.
• Defensive value: For anyone still being approached on this family, this is the strongest single authority: claim 1 of '066 (and the rest of claims 1‑13 and 18‑43) has been adjudicated invalid under § 102(b).
• Source: https://www.courtlistener.com/opinion/2526031/affymetrix-inc-v-pe-corp/

Strategic summary

Claim status. There is no PTAB claim-cancellation record for US 4,458,066, so the § 315(e) estoppel framework — which is what this analysis normally turns on — simply does not apply. What exists instead is a district court judgment: claims 1‑13 and 18‑43 of the '066 patent were held invalid under § 102(b) (Affymetrix, 306 F. Supp. 2d 363). To be precise about what that decision does not say: it did not address every claim of the patent, and the EPO counterpart proceeding (notice of deficiency dated 1983-11-12) attacked a partially overlapping set — claims 1‑24, 27, 29 and 30 — on novelty grounds. Claims outside 1‑13 and 18‑43 are best described as untested by the S.D.N.Y. ruling, though the reasoning (CIP broadened beyond the parent's § 112 disclosure) reaches any claim requiring an inorganic polymer support broader than silica gel or a phosphate protecting group broader than methyl.

Estoppel landscape. Because no IPR/PGR/CBM was ever instituted or terminated by final written decision, § 315(e)(2) estoppel is empty — it is not a constraint on anyone. Any defendant is free to run affirmative invalidity on any theory: § 102(b) on the 1980 Tetrahedron Letters article, § 112 ¶ 1 written-description attacks on the CIP's priority claim, § 103 combinations, or inequitable conduct (which survived summary judgment in 2004 and, on the record described, was a live issue). The real constraint is the opposite: the patent expired 2001-07-03, so there is no prospective infringement to defend against. Damages exposure, if any, is limited to the pre-expiration window and is likely long since time-barred under § 286.

Pattern signals. No repeat petitioner — there is no petitioner at all. No defensive aggregator (Unified Patents, RPX, or similar) appears anywhere in this patent's chain of challenges; the Google Patents "Family has litigation" entries show only ordinary district court dockets (N.D. Cal. 3:97-cv-00118; D. Del. 1:00-cv-00629) arising from the Affymetrix/Applera/Competitive Technologies dispute. Ownership ran University Patents → Competitive Technologies, with an exclusive enforcement licensee (PE Corp./Applera). Modern citations to US 4,458,066 are overwhelmingly background/prior-art citations in third-party patents (e.g., phosphoramidite-synthesis descriptions in EP and WO specifications, and an exhibit in Nippon Shinyaku v. Sarepta, D. Del. 1:21-cv-01015) — not assertions. That pattern is what an expired foundational patent looks like in the literature.

Recommended next steps

• If you received a demand letter citing US 4,458,066: check the expiration date first — the patent's term ended 2001-07-03 per the legal-status record, and status is "Expired – Lifetime." Any demand covering post-2001 conduct is facially meritless, and any pre-2001 claim is barred by the six-year damages limitation of 35 U.S.C. § 286.
• If the assertion is against a claim in 1‑13 or 18‑43: the response is a straight cite to Affymetrix, Inc. v. PE Corp., 306 F. Supp. 2d 363 (S.D.N.Y. 2004) — https://www.courtlistener.com/opinion/2526031/affymetrix-inc-v-pe-corp/ — quoting: "we hold that claims 1-13 and 18-43 of the '066 patent and claims 1-7 and 21-24 of the '418 patents are invalid."
• Do not expect a PTAB fight. No IPR/PGR/CBM can be filed on an expired patent for past conduct in the ordinary case, and none was ever filed here. Do not plan litigation strategy around a stay pending PTAB review — there is nothing to stay for.
• Verify the enforceability issue if it ever matters. The inequitable-conduct claim survived summary judgment in 2004; whether it was ultimately tried and how it came out is something I could not confirm from the sources I could reach here. If unenforceability matters to your position, pull the full S.D.N.Y. docket 01-cv-00634 (S.D.N.Y.) and any subsequent Federal Circuit docket directly rather than relying on this summary.
• Where to check for anything I missed: PTAB E2E (https://ptacts.uspto.gov/ptacts/) and USPTO PatentCenter for the '066 patent's full file wrapper, plus the ODP API re-query — but as of the most recent ingest the structured block is authoritative and shows zero AIA proceedings.

I'll start by gathering what's verifiable about this patent's ownership records.

Let me dig into the specific litigation and ownership history references.

US 4,458,066 — Assignment Chain Reconstruction

Verification entry points:

• USPTO Assignment Center: https://assignmentcenter.uspto.gov/ (search patent 4458066)
• Google Patents legal events: https://patents.google.com/patent/US4458066/en
• Family litigation index (Darts-IP): https://patents.darts-ip.com/?family=26824202

Methodological caveat, read first. My tooling could not retrieve the USPTO Assignment Center record itself (no direct query access to the reel/frame index in this session). Everything below that is stated as fact comes from the Google Patents bibliographic/legal-events record captured in the authoritative full text supplied for this patent, plus two named litigation docket links surfaced on that same page. I have no reel/frame numbers and no correspondent of record for any link in this chain, and I will not invent them. Where a field is empty, it is empty because it is unverified — not because the record is clean.

Inventors

Unusual patterns worth flagging:

1. The inventors assigned to a third-party licensing company, not to their university. The chain runs inventors → University Patents, Inc., not → The Regents of the University of Colorado. The full text records: "1983-05-18 — Assigned to UNIVERSITY PATENTS, INC. — ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: MATTEUCCI, MARK D., CARUTHERS, MARVIN H." Google Patents lists University Patents Inc as both original assignee and current assignee. A separate private patent-management company sitting between the inventors and their university is a structural fact, not a naming inference.
2. Federally funded. The spec states: "The inventions described herein were made in the course of work under a grant or award from the Department of Health, Education and Welfare." This is a Bayh-Dole-era invention with a government-interest statement, which is consistent with (but does not prove) a university-tech-transfer routing.
3. No "inventor departure" signal in the portfolio-fire-sale sense. Both inventors were never employees of the assignee, so the "all inventors leave within 12 months" heuristic does not apply here — it is not present / not applicable.
4. The application is a continuation-in-part of Ser. No. 126,025, filed 1980-02-29, now abandoned. The 1980 priority date is carried forward. Family members sharing that priority include US 4,500,707 (priority to US 06/358,877) and US 5,132,418 (priority to US 06/601,813) — the other Caruthers phosphoramidite/phosphite patents.

Original assignee

University Patents, Inc. (legal name as recorded: UNIVERSITY PATENTS, INC.; Google Patents renders it University Patents Inc).

• Line of business: Patent management and technology licensing — an intermediary that acquired and out-licensed rights in university-origin inventions. It is not an operating company: it does not ship a product embodying claims 1–11 (a process for stepwise polynucleotide synthesis on a derivatized silica support). No product embodies the claim in commerce because the claim is a process, and the assignee's business model was licensing that process to instrument/reagent makers.
• Product embodying the claims: None by the assignee itself. The commercial embodiment of this chemistry in the 1980s–90s was automated DNA synthesizers and phosphoramidite reagents (Applied Biosystems and others), which were licensees, not the patent owner.
• Current status: Unverified. I could not confirm whether University Patents, Inc. is operating, acquired, or dissolved. Google Patents still prints "Current Assignee (the listed assignees may be inaccurate): University Patents Inc" — but that field is populated algorithmically from the last recorded assignment, not from any current corporate-status check, and it should not be read as a live ownership statement. Treat the present-day owner as unknown.
• Legal status of the patent itself: Expired – Lifetime, with "Anticipated expiration" recorded 2001-07-03 (17 years from the 1984-07-03 grant). "Expired – Lifetime" rather than "Expired – Fee Related" indicates the term ran out naturally; maintenance fees were paid. Any present-day assertion would be impossible — the subject matter has been in the public domain for roughly 25 years.

Assignment timeline

One recorded assignment appears in the legal-events record. No post-issuance transfers are recorded.

• 1983-05-18 (recorded same date per Google Patents legal events) — Reel not retrieved / not verified

  • Conveyance: Assignment of Assignors' Interest
  • Assignor: Mark D. Matteucci and Marvin H. Caruthers (joint inventors)
  • Assignee: University Patents, Inc.
  • Correspondent: Unverified — I could not retrieve the correspondent of record. No attorney, firm, or address attributable to this recording appeared in any source I could reach. Note that the original prosecution correspondence in the full text of the patent is not the same thing as the assignment-record correspondent, and I am not substituting one for the other.
  • Context: Original inventor-to-licensing-company assignment of the initial right, executed roughly two years after the 1981-03-24 CIP filing and about fourteen months before the 1984-07-03 grant.

• No further assignment, security agreement, merger, change of name, license, or release is recorded in the indexed legal events through the 2001-07-03 expiration. Specifically: no transfer to an LLC, no transfer to any entity on the NPE lists in the brief, and no defensive aggregator in the chain.

Litigation flagged on the family (no assignment attached to either):

• California Northern District Court, case 3:97-cv-00118 — https://portal.unifiedpatents.com/litigation/California%20Northern%20District%20Court/case/3%3A97-cv-00118
• Delaware District Court, case 1:00-cv-00629 — https://portal.unifiedpatents.com/litigation/Delaware%20District%20Court/case/1%3A00-cv-00629

I could not retrieve the case captions, the parties, or the patents-in-suit for either docket. Both predate the 2001 expiration, so both were live-term assertions. I cannot state who asserted or who was accused, and I will not guess.

Timeline diagram

timeline
    title Ownership of US 4458066
    1980 : Parent application filed
    1981 : CIP application filed
    1983 : Assigned to University Patents Inc
    1984 : Patent granted
    1997 : Suit filed in N D California
    2000 : Suit filed in Delaware
    2001 : Patent expired

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No transfer of this patent to any "IP / Patents / Licensing / Holdings / Ventures" entity is recorded. The only recorded link is the 1983-05-18 inventors-to-University Patents assignment. University Patents, Inc.'s licensing-focused name is not a finding: naming alone is excluded by the brief, and no registered-agent address, single-member LLC formation, or no-products-in-commerce evidence is in hand.

2. Known asserter in the chain — not present. No assignee in the record matches Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg entity. University Patents, Inc. is a university-technology-transfer intermediary, not a high-frequency plaintiff on Unified Patents' or RPX's asserter directories as far as I could determine — and I found no directory entry either way.

3. Repeat correspondent across the chain — unclear. There is only one recorded link in the chain, so the "recurrence" test cannot be run by definition. More importantly, I could not retrieve the correspondent of record at all. This signal is unassessable, not negative.

4. Cascading transfers — not present. One assignment in 43 years of record. No chained LLCs, no sub-24-month sequences, no shared correspondent addresses observable.

5. Pre-litigation transfer — not present. The 1997 N.D. Cal. and 2000 D. Del. suits were filed 14 and 17 years after the only recorded assignment. Nothing was transferred in the six months before either filing.

6. Bankruptcy fire-sale — not present. No Chapter 7/11 sale of this patent is recorded, and no Kodak/Nortel/Polaroid-style transaction touches it. That University Patents, Inc.'s post-2001 corporate fate is unverified means I cannot rule out a later asset disposition — but nothing would have been assertable after 2001-07-03 anyway.

7. Privateering — not present. No operating company transferred this patent to an NPE. The flow runs the other direction: individual academic inventors → licensing intermediary.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. The patent was not "neutralized" by acquisition; it simply expired.

Verdict

Insufficient data.

Justification: the entire recorded chain is a single link — the 1983-05-18 assignment from inventors Matteucci and Caruthers to University Patents, Inc. — with no post-issuance transfer of any kind through the 2001-07-03 expiration, which is the brief's own stated condition for this verdict ("no records, or only the original assignment"). I could not retrieve the reel/frame or the correspondent of record for that single entry, and the two flagged docket numbers (3:97-cv-00118, 1:00-cv-00629) could not be resolved to parties, so the two assertive 1997/2000 litigations cannot be attributed to any assignee with confidence. One observation does deserve to survive the verdict: the original assignee is a licensing intermediary rather than a product manufacturer, so this patent was never owned by an operating company shipping an embodiment — but that is a structural descriptor of university tech transfer circa 1980, not evidence of an NPE chain, and the brief's rule against naming-based inference applies.

Verify at: https://assignmentcenter.uspto.gov/ (search patent number 4458066) — specifically request the reel/frame and correspondent for the 1983-05-18 recording, which are the two gaps that would move this to a real finding.

I'll search for the specific patent and its cited prior art references.

Let me verify the exact references cited on the face of this patent and check the cited U.S. patents mentioned in the specification.

Let me verify the identity of the prior-art U.S. patents named in the specification and confirm the face-of-patent citations.

Prior-Art Analysis — U.S. Patent No. 4,458,066

Note on sources/caveats up front: I could not issue a query directly against USPTO Patent Public Search / PatentCenter in this session; the results below are grounded in (a) the authoritative full text of US 4,458,066 you supplied, (b) the Google Patents/Espacenet bibliographic records, and (c) a faithful reproduction of the printed front page of U.S. 4,458,066 published in Biotechnology Law Report 4(7–8), p. 260 (1985) ("BLR 408"). Where I could not independently verify a number, I say so rather than guessing. I have not auto-corrected any identifier; numbers are reproduced exactly as printed.

1. The patent, identified literally

The Feb. 29, 1980 parent date is the relevant pre‑AIA § 102(b) cutoff: a printed publication or patent dated before Feb. 29, 1980 (one year before the parent filing) is § 102(b) art; anything between Feb. 29, 1980 and Mar. 24, 1981 is at most § 102(a)/§ 103 art.

2. What is actually "cited" on this patent

This is the most important finding, and it cuts against the premise of the question:

On the face of US 4,458,066 there is exactly one reference listed under "[56] References Cited," and it is a journal article — not a patent:

[56] References Cited — PUBLICATIONS
Köster, H., Tetrahedron Letters, pp. 1527–1530, 1972.

There are no U.S. Patent Documents listed on the face of 4,458,066. (This distinguishes it from its sibling, US 4,415,732, whose face does list US 3,534,017.) Note also that Espacenet's "cited documents" view for the corresponding record returns "No documents available for this priority number," i.e., no cited-document data is indexed there either.

So there is no "each patent citation" to walk through — the answer to "which patents did the examiner cite?" is none. What follows therefore separates (A) the one face-of-patent citation, and (B) the prior art the applicants themselves discussed in the specification body, which is where the U.S. patent numbers appear.

3. Face-of-patent citation

3.1 Köster, H., Tetrahedron Letters, pp. 1527–1530 (1972)

• Full citation: H. Köster, "…," Tetrahedron Letters (1972), pp. 1527–1530.
• Date: 1972 — well before Feb. 29, 1980 → potential § 102(b) art.
• Description (as characterized in the '066 specification): attachment of nucleoside phosphates to silica gel using a trityl linking group. The specification states the method "is apparently applicable only to pyrimidine nucleosides," and that cleavage of the nucleoside from the silica support "can only be accomplished with acid, to which the purine nucleosides are sensitive."
• Potential § 102 anticipation: None of claims 1–43. Köster's support–nucleoside bond is an acid-labile trityl linkage and is limited to pyrimidine nucleosides, whereas independent claim 1 (and claims 7 and 13) require the inorganic polymer to be "linked to the 3′ or 5′‑O— of the nucleoside through a base hydrolyzable covalent bond" (claim 13 specifically an ester linkage formed through the 3′‑OH). Köster discloses neither a base-hydrolyzable ester linkage nor the phosphite/phosphate triester (R₁ = hydrocarbyl) element common to the composition claims. Köster is thus, at most, § 103 background — and the specification is drafted precisely to distinguish it. No § 102 rejection can be sustained on this reference alone.

4. Prior-art U.S. patents named in the specification body

The specification states (in the section on preparing the support) that functional groups on silica suitable for reaction with the nucleoside hydroxyl "can be effected using known methods, e.g. methods described in":

U.S. Pat. Nos. 3,519,538; 3,419,517; 3,652,761; and 3,669,841.

(These numbers are reproduced exactly as printed; I have not silently corrected them.)

Potential § 102 anticipation for claims 1–43 (for all four of these): None. These patents teach how to attach proteins/enzymes to silanized inorganic supports — i.e., how to create the functionalized, reactive inorganic polymer. They are silent on:

• nucleosides, nucleotides, oligonucleotides;
• base-hydrolyzable ester linkages through the 3′‑ or 5′‑O of a nucleoside;
• phosphite/phosphate triester linkages (the R₁ hydrocarbyl element of claims 1, 7, 13, 18, 34, 43);
• condensation of a support-bound nucleoside with an activated nucleoside phosphite.

They supply, at most, the "functionalized inorganic polymer" starting-material teaching recited in the preamble of claims 34/43 — and a preamble teaching of an otherwise-known support does not disclose the condensing step that is the heart of those process claims. No anticipation; § 103 relevance only.

5. Non-patent prior art named in the specification body

5.1 V. Amarnath and A. D. Broom, Chemical Reviews 77, 183–217 (1977)

• Date: 1977 → potential § 102(b) art.
• Description: A review of polymer-supported oligonucleotide synthesis. The specification cites it for the classical problems of organic polymer supports — slow diffusion of activated nucleotides, excessive swelling of macroporous low-crosslinked supports, and irreversible reagent absorption.
• Potential § 102 anticipation: None. A general review that does not disclose the specific modified inorganic polymers of claims 1/7/13, nor the specific condensation step of claims 18/34/43, cannot anticipate. It is § 103/background art only. (A reference "must disclose all elements" — Amarnath & Broom discloses no element of the base-hydrolyzable ester/silica support recited in the claims.)

5.2 R. L. Letsinger and W. B. Lunsford, J. Am. Chem. Soc. 98(12), 3655–3661

• Date: JACS vol. 98 = 1976 (the specification gives no year) → potential § 102(b) art if 1976 as indicated.
• Description: Production of phosphotriester derivatives of oligothymidylates by reacting a phosphorodichloridite with a 5′‑O‑blocked thymidine, then reacting the product with a 3′‑O‑blocked thymidine, oxidizing the phosphite to a phosphate, and removing blocking groups — yielding dTpTpTpT (tetramer) and dTpTpTpTpT (pentamer), all in solution. The specification criticizes it because "the process requires separation and purification of products at each stage."
• Potential § 102 anticipation: None of the composition claims (1, 7, 13) — Letsinger's products are free solution-phase phosphotriesters, not nucleosides covalently bound to an inorganic polymer. None of the process claims (18, 34, 43) either, because each of those expressly requires the starting nucleoside/oligonucleotide to be "covalently linked to an inorganic polymer" (claim 18) / "silica covalently bound to the nucleoside by the group —Z₁NHCOZCO—" (claim 34) / "a nucleoside linked to a functionalized inorganic polymer" (claim 43). Letsinger's solution chemistry is § 103 art of the first order (it is the phosphite-triester chemistry the invention builds on), but it is not an anticipation.

6. Bottom line

Conclusion: No reference cited on or discussed in US 4,458,066 discloses every element of any of claims 1–43. The single face-of-patent citation (Köster 1972) is a § 103-comparable reference that the specification expressly distinguishes on the acid-labile trityl linkage / pyrimidine-only limitation; the four U.S. patents are inorganic-support functionalization art that supplies the support but none of the nucleoside-phosphite condensation chemistry; and Letsinger & Lunsford is the closest process chemistry but is explicitly solution-phase and lacks the "linked to an inorganic polymer" element required by claims 18, 34, and 43. On these references the record supports validity over § 102, and any challenge would have to be framed as § 103.

7. Two things worth flagging beyond the citations

1. Family / interference context. The record shows the application is in the Caruthers chain that also produced US 4,500,707 (Ser. No. 358,877) and US 5,132,418 (Ser. No. 601,813, the application involved in Itakura v. Caruthers, Patent Interference No. 101,724, decided June 11, 1991, in which judgment on the count was awarded to Caruthers and Matteucci). Interference No. 101,724 pitted the '066 family against Itakura, U.S. Pat. No. 4,373,071. If you want a true § 102/§ 103 picture, Itakura '071 and the Caruthers assertion that "none of his claims would have been obvious over the references cited" are relevant secondary evidence, even though '071 is not a face citation of '066.
2. The claim text I am reasoning from is not the certified claim set. The claim language used above (claims 1, 7, 13, 18, 34, 43) comes from the published reproduction in Biotechnology Law Report; the OCR is partly garbled (e.g., the structure drawings collapse into stray "O/R/O" fragments, and "each A is H or OR" is truncated). For an element-by-element § 102 chart, you should pull the certified printed claims from the USPTO image file. My no-anticipation conclusion is robust to this because the distinguishing elements I rely on (base-hydrolyzable ester linkage; support-bound nucleoside; R₁ hydrocarbyl phosphite/phosphate triester; silica–Z₁NHCOZCO– linkage) are consistently recited across the reproduced independent claims and in the specification.

If you can confirm the identity of US 3,419,517, US 3,652,761, and US 3,669,841 (or supply the certified claim set), I'll convert the table in § 6 into a formal element-by-element § 102 chart.

I'll verify the patent's face-of-record references and claim scope before analyzing.

Let me pull the full claim set and the face-of-record references.

The claim set is critical. Let me retrieve the actual claims and any validity/reexamination history.

Obviousness Analysis — U.S. Patent 4,458,066 (Caruthers & Matteucci)

Note on the record. The full text of US 4,458,066 is the authoritative source here. Google Patents supplies the disclosure, the family, and the litigation/legal-status data, but the scraped text does not include the printed claims. The only verbatim claim language I recovered is claim 1, reproduced in a litigation-report reprint of the patent (Biotechnology Law Report, "BLR 389," snippet: "1. A modified inorganic polymer represented by the formula: … wherein ⊙ is an inorganic polymer linked to the 3′ or 5′-O— of the nucleoside through a base hydrolyzable covalent bond; R is H or a blocking group; R₁ is a hydrocarbon radical containing up to 10 carbons; each B is a nucleoside or deoxynucleoside base; and each A is H or OR."). Everything below about the process claims is derived from the patent's own specification and from the near-identical claims of the sibling continuation US 5,153,319 (https://www.everypatent.com/comp/pat5153319.html), and is flagged as an inference, not as verified claim text. See "Confidence and gaps" at the end.

1. Legal framework and effective filing dates

Because the application was filed before 2013-03-16, pre-AIA 35 U.S.C. § 103 governs, as construed by Graham v. John Deere, 383 U.S. 1 (1966), and KSR Int'l v. Teleflex, 550 U.S. 398 (2007).

Critical date analysis for § 103:

• Subject matter carried over from abandoned Ser. No. 126,025 gets the 1980-02-29 date; matter first added in the 1981 CIP gets only 1981-03-24 (see § 112 written-description/priority support for each claim).
• Every reference identified in the patent's own Prior Art section predates both dates by far more than one year, so all are § 102(b) art that the applicant cannot swear behind. This matters: the inventors' own contemporaneous publications (Matteucci & Caruthers, JACS 103:3185 (1981); Beaucage & Caruthers, Tetrahedron Lett. 22:1859 (1981)) post-date the 1980-02-29 filing, are the inventors' own work, and are therefore not available as prior art. The obviousness case must be built from Koster, Letsinger, Amarnath & Broom, the four functionalization patents, and the general knowledge of the art.

2. The reference set (as identified in the patent's own Prior Art section)

The patent also relies on the inventors' admissions in the specification: that the goal (rapid, high-yield, sequence-defined, solid-phase oligonucleotide synthesis) was long sought, that prior polymer supports were inadequate, and that the Letsinger phosphite route "requires separation and purification of products at each stage." Those admissions are usable as evidence of the state of the art and of the problem to be solved.

3. Claim taxonomy (inferred)

1. Group A — Composition claims (claim 1, and dependents): a "modified inorganic polymer" comprising an inorganic polymer (silica being expressly the preferred species) joined to the 3′- or 5′-oxygen of a nucleoside by a base-hydrolyzable covalent bond, with R = H or blocking group, A = H or OR (deoxy or ribo), B = nucleoside base, R₁ = hydrocarbon radical of up to 10 carbons.
2. Group B — Support-preparation process claims: (a) treating silica with a coupling agent having a reactive group; (b) converting silica to amino-silica (aminoalkylsilane); (c) mono-succinylation of the nucleoside via the dicarboxylic anhydride; (d) carbodiimide-mediated condensation to give the ester-linked nucleoside–silica; (e) capping residual reactive groups. (Reflected verbatim in the sibling continuation US 5,153,319, claims 1–13.)
3. Group C — Synthesis-cycle claims: condensation of the support-bound nucleoside's free 5′- (or 3′-) OH with an activated nucleoside phosphite, capping of unreacted hydroxyls, oxidation of phosphite → phosphate, removal of the 5′-protecting group (detritylation), repetition, and base hydrolysis to release the oligonucleotide.

4. Combination 1 — Koster (R1) + Letsinger/Lunsford (R2) + Amarnath & Broom (R3) → renders Groups A and C obvious

Element-by-element mapping (claim 1):

For Group C (the cycle): R2 supplies (i) P(III) phosphite coupling through a phosphorodichloridite/monochloridite, (ii) oxidation of the resulting phosphite to a phosphate, and (iii) removal of blocking groups — i.e., a three-step cycle. R2 supplies the phosphite-coupling and oxidation steps exactly. The only added step is the optional capping of unreacted hydroxyls, which the specification itself concedes is a "traditional" technique (acetic anhydride; phenyl isocyanate).

Why a PHOSITA would have combined them (motivations, all sourced to the record):

1. Both references are aimed at the same problem — stepwise, sequence-defined oligonucleotide synthesis. KSR asks whether the combination is "the predictable use of prior art elements according to their established functions." Here the elements perform exactly their established functions: Koster's silica-immobilized nucleoside is a synthesis start point; Letsinger's phosphite chemistry is the internucleotide bond-forming reaction.
2. R2's own admitted shortcoming supplies the express motivation. The patent states that Letsinger's method "requires separation and purification of products at each stage to ensure proper sequencing of the added nucleosides." Executing R2's chemistry on R1's insoluble silica support eliminates exactly that problem — the support is the separation medium. This is the classic reason a solution-phase process is moved onto a solid support, and it is the same reasoning that produced Merrifield peptide synthesis, then well known in the art.
3. R3 expressly diagnoses the defect of the then-used organic polymer supports (slow diffusion, swelling, irreversible adsorption) and thereby directs the artisan to a rigid, non-swelling, non-adsorbing inorganic matrix. Koster had already demonstrated that silica works as such a matrix for nucleosides.
4. R1's own limitation points directly at the claim-1 difference. Koster's link is acid-cleavable, and the patent itself admits purine nucleosides are acid-sensitive. The artisan reading R1 is expressly told that (a) a silica-supported nucleoside is workable and (b) the linker chemistry is the problem. Selecting an ester or amide linkage (universally recognized as base-labile and stable to the neutral/basic, non-aqueous conditions of phosphite coupling) is the predictable fix, and ordinary ester/amide chemistry on silica was already routine (see Combination 2).
5. "Obvious to try" applies with particular force. As of 1980 the art had a finite, identified, and predictable set of candidate supports (polystyrene, cellulose, polyacrylamide vs. silica/porous glass) and a finite set of linker chemistries (acid-labile trityl; base-labile ester/amide; photolabile). Where the art identifies a problem and a small number of solutions, a PHOSITA's success is reasonably expected, not inventive.

Result: Claim 1 (Group A) and the Group C cycle claims (coupling via phosphite, oxidation, deblocking, repetition, base hydrolysis release) are, on this record, primâ facie obvious over R1 + R2 + R3.

5. Combination 2 — Amarnath & Broom (R3) + US 3,419,517 / 3,519,538 / 3,652,761 / 3,669,841 (R4–R7) → renders Group B obvious

Mapping: The patent expressly admits that the surface chemistry it uses is "prepared by art-recognized procedures," namely: reaction of a trialkoxy-3-aminopropylsilane with silica to install the aminoalkyl tether, reaction of the amine with a dicarboxylic anhydride (succinic anhydride) to install a carboxy terminus, blocking of residual silanols with a trialkylhalosilane, acylation of unreacted amines, and carbodiimide-mediated esterification of a nucleoside hydroxyl. It then points the reader to R4–R7 as teaching "the production of a variety of functional groups on the surface of the silica gel suitable for reaction with the hydroxy (3′- or 5′-) of the initial nucleoside."

Why a PHOSITA would combine: R4–R7 are the classic inorganic-support functionalization patents (silanization of silica/glass; amino- and carboxy-terminated tethers for immobilizing biological molecules). Once Koster (R1) and R3 have established silica as a desirable support for a nucleoside, applying the R4–R7 silanization/succinylation/carbodiimide toolkit to a blocked nucleoside is not an inventive leap; it is the routine use of a known toolbox for its known purpose. Residual-group capping with acetic anhydride is likewise "traditional" per the specification. In re Keller / MPEP 2143: "the test is what the combined teachings … would have suggested to those of ordinary skill in the art."

Result: Group B is obvious over R3 + any of R4–R7.

6. Combination 3 — R1 + R2 + R3 + R4–R7 (the four-way combination) → renders the whole of claim 1 obvious

This is the strongest single combination against claim 1 and against the method-of-making claims: Koster supplies the silica-bound nucleoside concept; Letsinger supplies the phosphite triester coupling/oxidation chemistry and thereby the reason to work on a support; Amarnath & Broom supplies the express motivation to abandon swelling organic supports in favor of rigid inorganic ones and catalogues the failure of prior efforts; R4–R7 supply the enabling linker chemistry, including the carboxy-functionalized silica that makes an ester (base-hydrolyzable) linkage to a nucleoside a matter of routine application.

Adding R8 (Letsinger 1966, insoluble polymer support) supplies an independent teaching that stepwise oligonucleotide synthesis on an insoluble support was already a recognized strategy.

7. Discrete limitations and their individual obviousness postures

8. Combination 4 (tentative) — R1 + R2 + the known azole/heterocycle activation chemistry → against the activated-phosphite claims

R2 uses halogen (chloro) as the phosphite leaving group. The claims at issue in the family extend to phosphites in which X is a nitrogen-heterocycle-derived secondary amino group (tetrazole, triazole, nitroimidazole, etc.). An obviousness attack would require a pre-1980 reference teaching (i) nucleoside phosphorochloridites and (ii) their conversion to azolides/heterocyclyl phosphines, or the use of azoles as nucleophilic activators of P(III) electrophiles. I do not have such a reference in the provided materials, and I will not fabricate one. The patent itself asserts these compounds "are new compounds which are particularly useful" and "more reactive and consequently more efficient than the corresponding compounds wherein X is halogen" — an assertion of unexpected superiority that, if supported, cuts against obviousness for that subgenus. This combination is therefore flagged as unverified/needing a specific reference.

9. Graham / KSR factor-by-factor application

A. Scope and content of the prior art. R1–R8 span the two necessary disciplines: nucleotide phosphite chemistry (R1, R2, R8) and inorganic-support surface chemistry (R4–R7), with R3 supplying the state-of-the-art survey that links them by diagnosing the failure of organic supports.

B. Differences between the prior art and the claims. Genuinely, the only clear structural difference over R1 is the nature of the covalent linkage (base-hydrolyzable ester/amide vs. acid-labile trityl), and the only clear process differences over R2 are (i) performance on a solid support and (ii) the insertion of a capping step. Differences over R2 alone are the support itself.

C. Level of ordinary skill. A Ph.D. chemist/biochemist with a few years' experience in nucleotide or oligonucleotide chemistry and in polymer-supported (solid-phase) synthesis — a person for whom silanization, succinylation, carbodiimide coupling, trityl protection, and phosphite coupling/oxidation were all standard unit operations.

D. Predictability. Every claimed element performs its known function: a rigid inorganic matrix is known not to swell; an ester is known to hydrolyze in base; a phosphite triester is known to oxidize to a phosphate triester; a trityl group is known to be removable with acid. There is no new mechanism and no unpredictable result required by the claim language.

E. Secondary considerations (as they would be argued and evaluated).

• Long-felt need / failure of others: both favor the patentee. The patent's own recitation ("still remains a difficult and time consuming task, often with low yields") plus R3's catalogue of failures with organic supports supports a long-felt need — but note that Koster had already used silica, so the need was for linker/chemistry improvements, not for the support concept itself.
• Unexpected results: the specification reports ≥95% per-addition yields, 2–3 hours per cycle, and insensitivity of yield to chain length, plus a 64% overall yield to a deoxydecanucleotide. If demonstrated against the closest prior art (R2's solution-phase phosphite route, which required a purification per step), this could rebut a prima facie case for the process claims. Note the burden: evidence must be commensurate in scope with the claims — broad formula-I claims covering any inorganic polymer and any hydrocarbyl linker are unlikely to be carried by data on succinyl–aminopropyl–silica.
• Commercial success / industry adoption: the family's footprint (Applied Biosystems' automated synthesizers, the phosphoramidite patents 4,415,732/4,500,707/4,668,777, and the two litigations noted on the Google Patents record) is powerful if a nexus to the claim is shown. Practically, however, commercial success is attributable to the whole family's chemistry, not necessarily to the breadth of claim 1 here.

F. Overall. On the merits, a strong prima facie § 103 case exists against claim 1 and the Group B/C claims on the R1 + R2 + R3 + (R4–R7) combination, and against the Group B claims on the R3 + R4–R7 combination. The most defensible pockets are (i) the Lewis-acid (ZnBr₂) detritylation limitation and (ii) the specific heterocyclyl-activated phosphite compounds, neither of which I can currently defeat on the record available. Note also that breadth itself invites attack under § 112(a)/(b) (an "inorganic polymer" claim element covering silica, porous glass, aluminosilicates, borosilicates, metal oxides, and clays, with a function-only linker description, is enabled only at the silica/succinate example), though that is outside the § 103 question asked.

10. Practical conclusion

• Most probable § 103 rejections (if this were examined today, treating the 1980 date as controlling):

1. Claim 1 over Koster + Letsinger/Lunsford + Amarnath/Broom, further in view of US 3,419,517 / 3,519,538 / 3,652,761 / 3,669,841.
2. Support-preparation claims over Amarnath/Broom + US 3,419,517 / 3,519,538 / 3,652,761 / 3,669,841.
3. Cycle claims over Letsinger/Lunsford + Letsinger 1966 + Koster, with capping by routine acetic anhydride/phenyl isocyanate blocking.

• Probable survival points: ZnBr₂/nitromethane detritylation (absent a specific pre-1980 reference), and the specific azolide-type activated phosphites if the asserted reactivity/efficiency advantage is substantiated.
• Practical observation: the patent expired 2001-07-03, so this analysis is retrospective; its most likely real-world use is as background for later-family validity or for defensive analysis of the phosphite-triester lineage.

11. Confidence and gaps (explicit)

1. Claims. I could not retrieve the complete printed claim set of US 4,458,066 from the provided materials. Only claim 1's text is quoted verbatim (from a litigation-report reprint snippet). The Group B/C claim characterizations rest on the specification's "Definitions" section and the near-identical claims of sibling US 5,153,319, and are stated as inferences.
2. R4–R7 (US 3,419,517; 3,519,538; 3,652,761; 3,669,841). I did not verify their titles, inventors, assignees, or issue dates; I rely solely on the applicant's own characterization (surface functional groups on silica gel reactive with hydroxy) plus their general reputation as inorganic-support/enzyme-immobilization patents. Treat titles/assignees as unverified.
3. Letsinger 1966 (JACS 88:5319) and Letsinger, Finnan, Heavner & Lunsford, JACS 97:3278 (1975) appear in the family's citation lists (from Re. 34,069) rather than in this patent's Prior Art section; I have flagged them as adjuncts.
4. R1/R2 bibliographic details are as printed in the patent: Koster, Tetrahedron Letters, 1527–1530 (1972); Letsinger & Lunsford, JACS 98:12, 3655–3661 (1976). Modern indexes render these as Tetrahedron Lett. 13(16):1527 and JACS 98(12):3655 — no correction intended.
5. ZnBr₂ detritylation prior art: I affirmatively do not know of a pre-1980-02-29 reference teaching it from the materials reviewed; I am not asserting that none exists.
6. Litigation outcome: the Google Patents record lists only case filings (N.D. Cal. 3:97-cv-00118; D. Del. 1:00-cv-00629) and a Darts-IP family-litigation link; I have no information on validity holdings in those cases and do not infer any.