Use of the general formula compound (I), or any salt thereof, for preparation of a pharmaceutical compound for the treatment of infectious illnesses, in particular for the treatment of helicobacter. Y equals NO 2 , COOH or SO 3 H; Z equals O, N or S; X 1 and X 2 are halogens which may be equal or different; and m and y take values from 0 to 3 and may be equal or different.