Synthesis and members of 3-aminopyridin-2-one based fragment library. i: Aryl/Heteroaryl boronic acid, Pd2(dba)3, XPhos, K3PO4, n-butanol, 120 °C. ii: TMS-Cl, NaI, acetonitrile. iii: Bis(pinacolato)diboron, KOAc, Pd(dppf)Cl2, dioxane, 80 °C. iv: Aryl/Heteroaryl halide, Pd(PPh3)4, Na2CO3, toluene, EtOH, H2O, 100 °C. v: TMS-Cl, NaI, acetonitrile. vi: H2SO4, 120 °C. vii: NaOH, Br2. For synthesis of compound 4, see Supplementary Data Fig. 1, and for the synthesis of compounds 7 and 8, see Supplementary Data Fig. 2.