4-[4-(dimethylamino)-1-(4-fluorophenyl)-1-buten-1-yl]-3-(hydroxymethyl)-benzonitrile is an impurity of Citalopram (C505000) which is an inhibitor of serotonin (5-HT) uptake. Citalopram (C505000) is used as an antidepressant. Molecular Formula: C20H21FN2O Molecular Weight: 324.39