1H and 13C NMR spectral data of p‐nitrobenzenesulfonamides and dansylsulfonamides derived from N‐alkylated o‐(purinemethyl)anilines

In recent years, purine bases have been the subject of extensive research that led to the discovery of thousands of biological active compounds, including antineoplastic ones. We synthesized a novel series of alkylated purines (1-9) with notable in vitro antiproliferative activities, low toxicity and systemic distribution after oral administration in vivo. The design of these compounds was based on the modifications of acyclic O,N-acetals, previously described by our research group as anti-proliferative agents. We have also prepared the 5-fluorouracil (5-FU) derivative (10) as a prototype compound. Finally, the fluorescent analogous (11-14) of the most active compounds were synthesized in order to study the in vitro and in vivo drug distributions. The pnitrobenzenesulfonyl group was interchanged with the dansyl group as a chromophore because of its similarity. Moreover, a fluorescence study of some anti-tumour drugs with a dansyl [5-(dimethylamino)naphthalene-1-sulfonyl] group in their structure that present no toxicity in vivo confirms the use of this chromophore in the design. Although the structure of these derivatives was determined by means of standard spectroscopic techniques (H, C NMR and MS), a detailed NMR study has been performed in order to unequivocally corroborate their structures. Herein, we report the H and C NMR unequivocal assignments of a series of anti-proliferative compounds. The spectra of the precursors and intermediate derivatives of the synthesis pathway for their preparation are also included.