Is there a patent specifically for urea formation or isocyanate in regorafenib synthesis?
I can’t answer this as written because the prompt does not include any patent text, patent number(s), assignee, or publication country/date to identify the specific “urea formation” or “isocyanate” step you mean. “Regorafenib synthesis” and “urea formation isocyanate” could refer to many different process routes and different patent families.
If you share at least one of the following, I can narrow to the relevant patent(s) and summarize them accurately:
- a patent publication number (e.g., WO…, EP…, US…)
- the assignee/company name
- the specific intermediate name used in the urea-forming step (the isocyanate or amine/urea precursor)
- a snippet of the claim or method text
What regorafenib urea-forming chemistry typically involves (isocyanate route)
Urea linkages in small-molecule drug synthesis are commonly made by reacting:
- an amine with an isocyanate (forming the urea), or
- an amine with a protected isocyanate equivalent, often under conditions that minimize side reactions (e.g., uncontrolled hydrolysis of the isocyanate).
In patent literature, “isocyanate” often names the key reactive intermediate that is coupled to an amine to form the urea moiety. The exact protected-group strategy, solvent, temperature, and sequence (isocyanate addition order, aqueous workup, and purification) can vary by process.
Without the provided patent documents, I can’t confirm whether regorafenib synthesis in your target patent uses an isocyanate-mediated urea-forming step, or how it is claimed.
How to find the right “isocyanate urea formation” patent for regorafenib (search keywords)
If your goal is to identify the patent that claims the urea-forming step using an isocyanate, searches usually focus on:
- “regorafenib” plus “isocyanate”
- “regorafenib” plus “urea formation”
- “regorafenib” plus the specific urea intermediate (amine name or isocyanate name)
- “regorafenib” plus “carbamoylation” or “carbamoyl”
- “regorafenib” plus key process terms like “coupling,” “deprotection,” “hydrolysis,” or “phosgene equivalent” (depending on how the isocyanate is generated)
Patent claims will often describe the urea formation as part of a multi-step route rather than as a standalone “urea formation” patent.
Can you specify the exact intermediate or reaction step you mean?
“Urea formation isocyanate” could refer to different stages, for example:
- generating an isocyanate intermediate in situ, then trapping it with an amine, or
- isolating an isocyanate, then reacting it with an amine to form the urea.
If you paste the reaction scheme name/labels (even just the names of the starting amine and isocyanate intermediate), I can match that to the likely patent claims and explain what those patents typically cover (process vs. compound scope, selectivity, conditions).
What I need from you to give a patent-specific answer
Send one of these and I’ll respond with a targeted, citation-ready answer:
1) the patent publication number(s), or
2) the assignee/company and approximate filing year, or
3) the intermediate/isocyanate name used in the urea-forming step, plus any excerpt from the claim.
Sources: None provided in your message.