Patents
US 11136331 B2: Methods of O-demethylation
- Granted
- 2021-10-05
- Filed
- 2018-10-12 application 16755719
- Type
- Utility · 19 claims
- Elsewhere
- Google Patents ↗ · USPTO patent document ↗ · USPTO Patent Center record ↗
Abstract
There is provided a novel process for the preparation of a compound of formula I, wherein R1, R2, W, Z and are as described in the description, by demethylation of a corresponding O-methyl derivative with a borohydride-based reagent. This process may be used in the preparation of buprenorphine.
Source: PVGPATDIS, file of 2026-04-10 (ipg211005.xml).
Assignees
| Assignee | Type | Place | Also on furp.org | Source |
|---|---|---|---|---|
| CAMBREX CHARLES CITY, INC. 9 patents | US company or organization | Charles City, IA | PVGPATDIS, file of 2026-04-10 |
Inventors
| Inventor | Place | Patents | Person page | Source |
|---|---|---|---|---|
| Pär Holmberg | Charles City, IA | 7 | PVGPATDIS, file of 2026-04-10 | |
| Lars Eklund | Charles City, IA | 9 | PVGPATDIS, file of 2026-04-10 | |
| David Adams | Charles City, IA | 1 | PVGPATDIS, file of 2026-04-10 | |
| Michael Letourneau | Charles City, IA | 1 | PVGPATDIS, file of 2026-04-10 | |
| Margus Eek | Charles City, IA | 5 | PVGPATDIS, file of 2026-04-10 | |
| Alo Soone | Charles City, IA | 1 | PVGPATDIS, file of 2026-04-10 |
CPC categories
| Subclass | Category | First group | Source |
|---|---|---|---|
| C07D | Heterocyclic compounds | C07D489/12 | PVGPATDIS, file of 2026-04-10 |
| A61K | Preparations for medical, dental or toiletry purposes | A61K31/485 | PVGPATDIS, file of 2026-04-10 |
Cooperative Patent Classification, as currently assigned (one row per subclass).
Assignments and security interests
| Recorded | What | From | To | Reel/frame | Source |
|---|---|---|---|---|---|
| 2025-04-11 | Security interest Security interest Assignment and assumption of intellectual property security agreement | ARES AGENT SERVICES, L.P., AS FORMER AGENT signed 2025-04-11 | BLUE OWL CAPITAL CORPORATION, AS NEW AGENT NEW YORK, NY | 70821/302 | ECORSEXC, file of 2026-09-25 |
| 2025-03-06 | Security interest Security interest Security interest | CAMBREX CHARLES CITY, INC. signed 2025-03-06 | ARES AGENT SERVICES, L.P., AS COLLATERAL AGENT NEW YORK, NY | 70421/947 | ECORSEXC, file of 2026-09-25 |
| 2020-05-18 | Assignment Assignment of assignor's interest | ADAMS, DAVID signed 2020-04-21 LETOURNEAU, MICHAEL signed 2020-04-22 EKLUND, LARS signed 2020-04-26 SOONE, ALO signed 2020-04-29 HOLMBERG, PÄR signed 2020-04-30 EEK, MARGUS signed 2020-05-06 | CAMBREX CHARLES CITY, INC. CHARLES CITY, IA | 52687/359 | ECORSEXC, file of 2026-09-25 |
Documents recorded with the USPTO Assignment Recordation Branch that list this patent. A security interest is a lender’s claim on the patent as collateral; a release ends it.
USPTO bulk data: PatentsView granted patents, disambiguated (PVGPATDIS) for patents, assignees, inventors, places and CPC categories; the USPTO Patent Assignment Dataset (ECORSEXC) for assignments and security interests. Patents filed in the last 20 years. No claims or full text. Links to other records are by name (and state): EXACT means the identical full name and state; FUZZY means a looser name match, with the confidence shown.