THE SYNTHESIS OF CERTAIN NOVEL AZINE 'C'-NUCLEOSIDES (PYRIMIDINE, (1,2,4)TRIAZINE, S-TRIAZINE, C-GLYCOSYL AMIDINE, AMIDRAZONE)

A new amidine precursor, 33, for "C"-nucleoside synthesis is reported. This glycosyl amidine was used in a new ring closure to give ethyl 2-((beta)-D-ribofuranosyl) pyrimidine-4-carboxylate (41). Different transformations provided the corresponding pyrimidine carboxamide, 42, thiocarboxamide, 45, carbxamidine, 48, and carboxamidoxime, 49 nucleosides. The 5'-phosphate of 50 was prepared and coupled using carbonyldiimidazole with AMP to give the corresponding NAD analog, 51. Pyrimidine "C"-nucleosides of this same class were prepared with various aldehydic derivatives at C-4. The thiosemicarbazone, 53, oxime, 54 and methyl hydrazine carbodithioate, 55, derivatives were prepared from the dimethyl acetal, 39. A novel ring closure gave a new class of 1,3,5 triazine "C"-nucleosides via the condensation of 33 with dimethyl cyanoiminocarbodithioate (56) to give 4-methylthio-6-((beta)-D-ribofuranosyl) 1,3,5 triazin-2-amine 57. Preparation of the corresponding sulfoxide, 58, diamino, 59, oxo, 60, and thiono, 61, compounds from 57 is also described. A 1,2,4 triazinone, 64, was synthesized from the novel "C"-glycosyl amidrazone, 63.