The second case study was ADD (compound 15d in ref ), a merged human butyrylcholinesterase (hBChE) inhibitor/cannabinoid receptor 2 (hCB2R) ligand and a therapeutic target for preventing learning impairments in Alzheimer's disease (Figure ). The baseline multi-step model failed to identify a synthetic route, while the mixed fine-tuned model predicts retrosynthetic disconnections similar to the literature route (Figure ). Reagents were omitted from the literature route to focus on the core synthons. While the mixed fine-tuned model deviated by not reproducing the carbamate disconnection of ADD to benzyl-protected phenol D1, instead using the pre-synthesised phenyl carbamate E2, it proposed subsequent disconnections featuring the same cyclisation, reduction, and S N Ar as the literature route to mutually predicted reactants E1, F1, G1, and G2. This further reaffirms the improved ring-breaking performance in multi-step retrosynthesis of the mixed fine-tuned model, where the baseline model failed for the benzoimidazole scaffold in ADD.