. . . . . "Nasri W. Badran, \"Microcrystalline 3-(alpha-acetonylbenzyl)-4-hydroxycoumarin (warfarin) and methods of making.\" U.S. Patent US4113744, issued April, 1960."@en . "4-Hydroxy-1-Benzopyran-2-One"@en . . . . . . . "1076-38-6"@en . . . . . . . . . . . . . . . . . "4-hydroxycoumarin"@en . . . . . . . . . "experimental"@en .