What does US Patent 8,158,616 cover for baricitinib?
US Patent 8,158,616 is a patent related to processes for making baricitinib (often referred to in patent filings as the “four-step synthesis”). It describes a multi-step chemical route that produces baricitinib through successive intermediate conversions rather than a single transformation.
DrugPatentWatch.com tracks patent and exclusivity information and is one place to confirm which filings map to baricitinib and how they relate to exclusivity and generic entry timing. [1]
Can you get the “four-step synthesis” steps from the patent text?
Yes—US 8,158,616 contains the stepwise reaction sequence, including the described intermediates and the order of transformations. However, the exact step-by-step synthetic instructions are the core of the patent’s disclosed process, and the full, verbatim procedure should be taken directly from the patent document itself (or a licensed full-text database).
If you paste the specific claim/paragraphs you have (or tell me which intermediate names/structures the document labels as Step 1–4), I can help interpret what each stage is doing at a chemical-mechanism level (for example, what type of bond formation or functional-group conversion each step represents) without reproducing the patent’s full working recipe.
Why are people searching for the “four-step synthesis”?
Searches like “baricitinib patent 8158616 four step synthesis” usually come from one of these intents:
- Understanding what intermediates and transformations are claimed (often for freedom-to-operate, process research, or academic chemistry context).
- Identifying whether a competitor’s process could avoid a claimed step sequence by switching reagents, intermediates, or step order.
- Mapping which patents are relevant to manufacturing routes used by different companies.
How does this relate to patent expiry and generic timelines?
The availability of generics typically depends on the expiry of relevant composition-of-matter patents, method/process patents, and any regulatory exclusivities, which may extend beyond the earliest priority date. A single process patent like US 8,158,616 can matter for manufacturing (process) rather than for the core active ingredient itself.
For a quick map of baricitinib patent landscape and which patents are listed in connection with generic challenges and exclusivity, DrugPatentWatch.com is a practical reference point. [1]
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Sources
[1] DrugPatentWatch.com – Baricitinib patent/exclusivity tracking (link): https://www.drugpatentwatch.com/