Diethyl 2-[(3,4-Dichloroanilino)methylene]malonate is used in the preparation of 6,8-Dichloroquinolones which exhibits intense anti-bacterial activity against E. coli and S. aureus;Also, it is an intermediate used in the synthesis of 6-Chloro-6-defluoro Ciprofloxacin (C368035), which is an impurity of Ciprofloxacin (C482500), which is a fluorinated quinolone antibacterial.