Chlorosuccinimide → 3-Chloro-1H-indazole-5-carboxaldehyde

Participants

Reaction Steps

To a solution of 4.0 g (27.4 mmol) 1H-indazole-5-carbaldehyde [preparation described in US 2005/0227968-A1 (Intermediate 1)] in acetonitrile (116 ml) were added 4.2 g (31.5 mmol) N-chlorosuccinimide at room temperature. The resulting solution was stirred under reflux for 12 h. The mixture was then concentrated under reduced pressure yielding a solid precipitate. This material was triturated with water, filtered, and dried under high vacuum for 12 h to give the title compound (4.8 g, 97% of th.) as a white solid.

Provenance & Evidence