Medicinal Chemistry
Hit-to-Lead & SAR Support
Analog synthesis and SAR iteration to move a screening hit toward a developable lead, with full analytical characterization at every round.
Sparge Chem supports hit-to-lead and structure-activity relationship (SAR) programs with analog synthesis and iterative design rounds, run by the same team responsible for our 1,000+ compound building-block catalog — so the chemists doing your analog synthesis already work daily with the heterocyclic and building-block chemistry most hit-to-lead campaigns draw on.
A typical engagement starts from a hit or lead series with an existing SAR hypothesis (yours, or one we help formalize from your assay data), and proceeds through rounds of analog design, synthesis, and characterization — each round informed by the data from the last. We don't claim in-house computational modeling or a specific therapeutic-area specialization; what we bring is fast, reliable synthesis turnaround on the analogs your team designs, plus route and building-block expertise when a proposed analog needs a non-obvious synthetic path.
Work is scoped under NDA, typically on a Fee-for-Service basis per design round or as a dedicated FTE engagement for longer campaigns — the same two models used across our custom synthesis work, since medicinal chemistry programs are custom synthesis with a design-iteration loop layered on top.
What's included
Analog synthesis
Synthesis of designed analogs from a hit or lead series, including heterocycle construction, ring modifications, and substituent scanning.
SAR iteration support
Each synthesis round is scoped against the SAR questions it's meant to answer, so batches come back with the substitution pattern and purity needed to read the resulting assay data cleanly.
Building-block-informed route design
Direct access to our own 1,000+ compound building-block catalog means some analog routes can start from a stocked intermediate rather than a from-scratch synthesis, shortening turnaround.
Full analytical characterization
NMR, LCMS, and purity data on every analog delivered, so downstream assay results aren't confounded by unresolved impurities.
Small-to-medium analog sets
Sized for iterative hit-to-lead work — typically single-digit to low-double-digit analog counts per round, not large diversity libraries.
How it works
Share the series and SAR question
Send the lead/hit series structure, the SAR hypothesis or assay data driving the next round, and the analogs you want made (or the substitution pattern you want explored).
Route assessment
We flag which analogs are straightforward and which need a non-obvious route, with an indicative timeline for the round.
Synthesis & characterization
Analogs are synthesized and fully characterized (NMR/LCMS/purity) before shipment.
Next round
Results feed the next design round — most engagements run several rounds back-to-back under the same NDA and FTE/FFS arrangement.
Track record
Process development for Zavegepant and Bemnifosbuvir intermediates
In-house process development work on Zavegepant and Bemnifosbuvir intermediates — evidence of the route-design depth the same team applies to medicinal chemistry analog work.
Common questions
Do you do in-house computational or modeling-driven design?
No — we synthesize the analogs your team designs (or helps us formalize from your assay data). Our strength is fast, reliable synthesis turnaround and building-block/route expertise, not in-house modeling.
What size analog sets do you typically handle?
Small-to-medium sets sized for iterative hit-to-lead work — single-digit to low-double-digit analogs per round is typical, not large diversity libraries.
Can you start from our existing building-block catalog?
Yes — where an analog route can start from a compound already in our 1,000+ building-block catalog, that shortens turnaround versus a from-scratch synthesis.
Is this covered under the same NDA/FTE terms as custom synthesis?
Yes — medicinal chemistry engagements use the same NDA-first, FTE-or-Fee-for-Service structure as our custom synthesis work.
Ready to discuss medicinal chemistry?
NDA before any technical discussion. 24-hour feasibility response.