TZ-S (Fig. 1) is an oral alkylating agent which is used for the treatment of Grade IV astrocytoma - an aggressive brain tumor, also known as glioblastoma multiforme.

Fig.1 TZ-S, namely 4-methyl-5-oxo-2.3.4.6.8-pentazabicyclo [4.3.0] nona-2,7,9-triene-9-carboxamide.

Sample preparation, particulary with labille compounds, may cause many analytical problems. Therefore, elaboration of suitable analytical mothods for both, routine manufacturing processes, and investigation of novel synthetic routes is very important. RP-HPLC technique was used for the optimization of synthesis and the determination of purity of TZ-S.

Synthesis of the active substance - TZ-S - was conducted in two different ways: the first one, consisted of five synthetic steps, while the other consisted of three steps. The presented methods are useful for both synthetic pathways and, are suitable for determination of product purity, as well as separation and identification of ampurities.

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