THE INVENTION RELATES TO COMPOUNDS HAVING FORMULA (I): WHEREIN: R1 REPRESENTS A HYDROGEN ATOM OR A (C1-C4)ALKYL GROUP R2 REPRESENTS A HYDROXYL GROUP, A THIOL GROUP, A (C1-C4)ALKYLOXY GROUP OR A THIO(C1-C4)ALKYL GROUP AND N IS AN INTEGER EQUAL TO 1 OR 2, IN THE FORM OF A BASE OR ACID ADDITION SALT, AS WELL AS IN HYDRATE OR SOLVATE FORM. THE INVENTION ALSO RELATES TO THE PREPARATION METHOD THEREOF AND TO THE USE OF SAME IN THERAPEUTICS.