What patent covers rolopitant’s spirocyclic synthesis?
“Rolapitant” is an NK1 receptor antagonist, and patent filings that describe its preparation typically focus on assembling (1) the macrocyclic/heterocyclic framework and (2) any intermediate “spirocyclic” ring-assembly steps used to reach the final scaffold. With only the question text provided, there isn’t enough information to identify the exact patent document (number, assignee, or jurisdiction) that specifically claims a “spirocyclic synthesis” route for rolopitant.
Which details do you need to find the right spirocyclic-synthesis patent?
To pinpoint the correct patent (and its claims around the spirocyclic intermediate), you usually need at least one of the following:
- Patent number or application publication (e.g., WO/EP/US publication)
- Assignee (company/owner)
- Jurisdiction (WO vs US vs EP, etc.)
- The specific spirocyclic intermediate name, structure, or example number from the claims
- The synthetic step description you’re looking for (e.g., “spirocyclization,” “spiro ring formation,” “spirocyclic intermediate,” “ring-closure”)
How to search for the specific spirocyclic step inside rolopitant patents
Common practical search terms that map well to “spirocyclic synthesis” language include:
- “rolapitant” combined with “spiro” or “spirocyclic”
- “spirocyclic intermediate” and “example” (or “preparation”)
- “spiro ring” / “spiro ring formation” / “spirocyclization”
- The intermediate’s generic descriptor if the patent lists it (often with a compound number like “Intermediate X”)
If you share a patent number or an assignee name, I can help you narrow to the exact document and extract the claim language most relevant to the spirocyclic synthesis step.
Is “spirocyclic synthesis” likely a claimed novelty or just a described intermediate?
In many drug-process patent families, the “spirocyclic” element may be claimed in two different ways:
- As a specific spirocyclic intermediate (process claims around making that intermediate)
- As part of a broader process claim that covers preparation of rolopitant using that intermediate, where novelty may come from conditions, reagents, catalysts, or purification/isolations rather than the mere existence of the spirocycle
This distinction matters because different patents in the same family may claim different pieces (intermediate vs end drug vs salt vs crystallization).
What I need from you to answer precisely
Reply with any one of the following, and I’ll identify the likely patent(s) and explain the spirocyclic synthesis coverage:
- A patent number (WO/US/EP) you have seen, or
- The company/assignee (e.g., the owner you suspect), or
- A link, or
- The spirocyclic intermediate’s name/structure/example number you’re targeting.
Sources
No source documents were provided, so I can’t cite specific patents. If you paste the publication number or text snippet you’re working from, I can produce a sourced, document-specific answer.