Synthesis of 4 arabinofuranosyl derivatives of the antitumor agent 3-deazaguanine is described. By the use of 13C and 1H NMR spectroscopy, the structures of these nucleosides were established to be .alpha. and .beta. pairs of N-7 and N-9 arabinosides of 3-deazaguanine. In contrast to 3-deazaguanine and its ribosyl derivative, the nucleosides described were inactive against Sarcoma 180 in mice at 100 mg/kg.