HIGHLY-FUNCTIONALIZED AMINO PYRAZOLES AS ANTIOXIDANT AGENTS: A PRELIMINARY SYNTHETIC ACCESSIBILITY STUDY

5-pyrazolyl urea derivatives showed interesting pharmaceutical properties. In particular, compounds 1 (Figure 1) showed promising antioxidant activity by inhibiting ROS formation in platelet. The free amino group on the pyrazole ring appear to be essential for the antioxidant activity whereas the substitution of the catechol moiety (X group, Figure 1) modulate the ability of the compound to block ROS formation. To further extend the SARs of derivatives 1 and evaluate the effect on the activity of the introduction of a N-phenyl substituent on the pyrazole scaffold, we planned the synthesis of new amino pyrazoles 2 (Figure 1). In order to assess the chemical accessibility to the desired compounds, synthetic path A and B (Scheme 1) were considered. Methylhydrazine and p-anisaldehyde were selected as template reagents. Despite literature data, path A proved to be ineffective as the cyclization reaction could not occur in a number of different experimental conditions. Path B led to the isolation of the desired compound as a mixture of the two possible N-methyl isomers in good yields. In the poster, the different synthetic conditions as well as the characterization of the obtained pyrazole isomers will be presented.