Derivatives of nitrogen mustard with attached amino acid radicals, process of their preparation and pharmaceutical composition and two-component system in which the derivatives are comprised

In the present invention there are disclosed precursors of the general formula I in which Re1 and Re2 represent independently on each other a chlorine atom, a bromine atom, an iodine atom, the group of the general formula {OSOi2Me} or {OSOi2-phenyl group}, X represents an oxygen atom, the group NH or the group -{CHi2-} and Y represents an oxygen atom. Those precursors are substrates for carboxypeptidase G2 (CPG2) and provide more efficient cytotoxic therapeutical substances if compared with so far known products of CPG2-catalyzed reactions. In the present invention there are also described a pharmaceutical composition and a two-component system in which those precursors are contained as well as a process for preparing those precursors. The preparation process consists for instance in reaction the compound of the general formula XVIII with the compound of the general formula II, in which the general symbols have corresponding meanings.