NOAC (II) is prepared from octadecylamine and 4-(1,2,4-triazol-1-yl)-1-beta-D-2',3',5'-tri-O-acetylarabinofuranosyl) pyrimidine-2(1H)-one (I) in dioxane. Yields are > 95%. Purity by HPLC is > 97.5%. Solvent residues (methanol, chloroform) are < 0.3%. NOAC has been analyzed by the following spectroscopic methods: H-1 NMR, C-13 NMR, C-13 DEPT NMR, IR and MS. The spectroscopic data of all methods used is consistent with the structure of NOAC.