2I0H:
reference: p38 MAP kinase inhibitors. Part 6: 2-Arylpyridazin-3-ones as templates for inhibitor design., Natarajan SR, Heller ST, Nam K, Singh SB, Scapin G, Patel S, Thompson JE, Fitzgerald CE, O'keefe SJ, Bioorg Med Chem Lett. 2006 Nov 15;16(22):5809-13. Epub 2006 Aug 30. PMID: 16945533

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).