Scheme 1.

Synthesis of 1H-indazole-4-carboxamide derivatives 10a–e, 11a–e, 12a–i. Reagents and conditions: (a) (i) Boc₂O, Cs₂CO₃, 1,4-dioxane, r.t., 0.5 h; (ii) 2-(2,6-dichloro-3,5-dimethoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, Pd(dppf)Cl₂, 1,4-dioxane:H₂O = 3:1, 100 °C, 2 h, 62.3%; (b) LiOH·H₂O, THF, 50 °C, 6 h, 76.2%; (c) (i) POCl₃, pyridine, 0 °C, 1 h; (ii) aniline, 0 °C, 10 min; (iii) r.t., 1.5 h, 60.5%–82.3%.