Citalopram impurity 9/Citalopram EP Impurity C Oxalate Salt/3-Oxo Citalopram Oxalate Salt/Citalopram Related Compound C Oxalate Salt/3-(3-Dimethylaminopropyl)-3-(4-fluorophenyl)-6-cyano-1(3H)-isobenzofuranone oxalate [ 1440961-11-4 ]