Pharma & Specialty Chemical Standards

Chlorzoxazone (IUPAC: 4-chloro-3-hydroxy-N-(4-methylphenyl)-2H-1,2-benzoxazin-6-one) is a benzoxazinone derivative with molecular formula C13H11ClN2O3 and molecular weight 278.58 g/mol. Structurally, it features a chloro substituent at position 4, a hydroxyl group at position 3, and a 4-methylphenyl ring. Therapeutically, it functions as a centrally acting muscle relaxant for spasticity. Physicochemically, it is a white crystalline solid with limited water solubility (pKa ~4.5). Its mechanism involves modulating central nervous system activity, potentially enhancing GABAergic transmission, without direct neuromuscular blockade.