Nouveaux dérivés iodés de la 4-hydroxy-coumarine et médicaments qui les renferment

The invention comprises 3-[a -(p-iodophenyl)-b - acetylethyl] - 4 - hydroxycoumarin and its preparation by (a) heating 4-hydroxycoumarin with p-iodobenzyl acetone, or (b) diazotizing 3 - [a - (p - aminophenyl) - b - acetyl - ethyl] - 4 - hydroxycoumarin and treating the diazo-compound with a solution of a soluble iodide or hydriodic acid, preferably in the presence of copper or cuprous iodide, and warming the solution. The compound of the invention modifies the properties of Vitamin K antagonists. 3 - [a - (p - Aminophenyl) - b - acetyl - ethyl] - 4-hydroxycoumarin is prepared by reduction of the corresponding nitro-compound or by reaction of the corresponding chloro- or bromocompound with ammonia under pressure.