Solid‐Phase Parallel Synthesis of a Tetrahydroindazolone Library Containing Three Unique Core Skeletons

We have developed a practical strategy for the regioselective synthesis of a 1‐(hetero)aryl‐3‐substituted tetrahydroindazolone library. The condensation of in situ generated arylhydrazine on solid supports with 2‐acylcyclohexane‐1,3‐diones ensured the efficiency of solid‐phase parallel synthesis. In addition , we introduced three unique core skeletons containing nitrophenyl, anilyl, and pyridyl groups to maximize the molecular diversity through a diverse display of polar surface area in 3D chemical space. A 162‐membered drug‐like tetrahydroindazolone library was constructed in an average purity of 92 % without further purification.