5-Carboxy-6-chloroindole, a precursor for p38 kinase inhibitor, was prepared from 4-amino- 2-chloro-3-iodobenzoicacid by following the Japp–Klingemann synthetic approach. The structures of the key intermediates were also confirmed by X-ray analyses. Computational analysis was helpful in understanding the importance of the substituents at the cyclization step of the synthesis.
