What patent covers “regorafenib synthesis” of an isocyanate intermediate?
I can’t identify a specific regorafenib synthesis patent tied to an “isocyanate” step from the information provided. “Regorafenib” is a marketed kinase inhibitor, but patent coverage depends on the exact intermediate, the exact isocyanate structure/position, the synthetic route, and the jurisdiction (US, EP, WO, etc.). Without those details (or at least a patent number, assignee, or publication name), there’s no reliable way to pinpoint the correct patent.
What details are needed to find the exact isocyanate-related regorafenib synthesis patent?
To locate the right patent record, you typically need at least one of the following:
- The isocyanate intermediate name or structure (or the preceding alcohol/amine precursor).
- The patent language describing the “isocyanate” (e.g., “R-NCO,” “aryl isocyanate,” “carbamate formation,” etc.).
- The assignee/company or inventors.
- The filing country or publication type (WO, EP, US).
- Any partial identifiers (WO number, US publication like US20xx/xxxxx, EP publication like EPxxxxxxx).
With one of those anchors, the search can be narrowed to the specific process claims and examples where an isocyanate is used.
Is “isocyanate” about making regorafenib’s core, or about a protecting-group step?
In process chemistry, “isocyanate” can appear in multiple contexts:
- Converting an amine (or equivalent) into an isocyanate, then into a substituted urea or carbamate.
- Reacting an isocyanate with an amine to form a urea linkage used in kinase inhibitor scaffolds.
- Handling the isocyanate itself as an intermediate rather than isolating the final urea/carbamate product.
Different patents claim different parts of that logic (intermediate preparation vs. the coupling step vs. a specific purification/workup). That’s why the exact intermediate definition matters for matching to a particular patent.
Why the “isocyanate patent” might not be the one you expect
Even if a patent’s examples mention an isocyanate, the enforceable protection might instead be on:
- A particular regio-/stereochemical outcome.
- A specific catalyst/reagent set, solvent system, or temperature/time window.
- A specific purification step (crystallization/seed, solvent exchange) that enables an impurity profile.
So “mentions isocyanate” is not the same as “covers regorafenib synthesis via isocyanate.”
If you share a patent number, what I can do next
If you paste any of the following, I can help map the isocyanate step to the exact claims and identify whether it’s truly the “isocyanate synthesis patent” you mean:
- WO/EP/US publication number
- Assignee name (e.g., company that filed the process)
- The reaction description line(s) from the patent (the step containing “isocyanate”)
Sources
No sources were used because no patent identifiers or intermediate details were provided.