AI retrosynthesis tools free online
ChemicalTool Reaction is an online retrosynthesis tool and retrosynthesis software for organic chemists. Paste a target SMILES or draw a chemical structure to run AI retrosynthesis, get ranked disconnections, and explore retrosynthetic route planning with optional library evidence.
Retrosynthesis prediction & planning
Use this page as a landing for retrosynthesis prediction, retrosynthesis planning, and retrosynthesis generator searches. The planner turns a molecular graph into candidate precursors—similar in spirit to a retrosynthesis calculator, but focused on practical building blocks and route diversity.
- SMILES to synthesis route — paste canonical SMILES and run AI search.
- Chemical structure retrosynthesis — draw the target in the structure editor.
- Retrosynthesis tools free — free daily quota after sign-in; no desktop install.
- Compare multiple routes, then enrich with literature / library evidence when available.
Why an online retrosynthesis tool?
Desktop retrosynthesis software is powerful but heavy. An online retrosynthesis tool lets you try ideas quickly from the browser— ideal for teaching labs, early route scouting, and SMILES-based ideation before committing to a full process chemistry package.
Learn the method
New to the topic? Read what is retrosynthesis in organic chemistry and how to do retrosynthesis, then return here to practice with real targets.
FAQ
Is this retrosynthesis software free?
Yes—ChemicalTool Reaction offers free AI retrosynthesis with a daily quota after you sign in. It runs in the browser as an online tool.
Can I go from SMILES to a synthesis route?
Paste SMILES (or draw the structure), choose max routes / time limit, and run AI retrosynthesis to get ranked precursor suggestions.
How is this different from a retrosynthesis calculator?
Classic calculators often score single transforms. This tool proposes multiple retrosynthetic routes and can attach library evidence for further checking.
References & tools
- ChemicalTool Reaction — AI retrosynthesis with optional library evidence.
- PubChem — compound identifiers and structure depictions (NIH/NCBI).
- Related: AiZynthFinder / synthesis planning literature for computer-aided retrosynthesis.