Synthesis and biological evaluation of new pyrazole- and tetrazole-related C-nucleosides with modified sugar moieties

Antioxidant and Antitumor Activities of New Synthesized Aromatic C-Nucleoside Derivatives

“…Synthesis of carbohydrazones 3a-e and 4. Condensative cyclization of carbohydrazone 3a with acetic anhydride in the presence of anhydrous sodium acetate gave a cyclized product that according to physical and chemical studies, could not be reconciled with the structure of 10a, that but rather was compatible with that of [1,3,4]oxadiazolo-[2,3-a]isoindole 10b. The infrared spectrum of this compound showed the disappearance of the carboxylic acid hydroxyl group, sugar hydroxyl groups, and CONH absorption bands.…”

“…A solution of 5-(2',3'-dihydroxytetrahydrofuran-1'-yl)-2-methylfuran-3-carbohydrazide (11) [4] in ethanol containing a few drops of acetic acid was treated with carbonyl compound, and the reaction mixture was refluxed on water bath for 30 min. After cooling the 3-carbohydrazones 12-14 that separated out were filtered off, washed with a little ethanol, and dried.…”

“…The carbohydrazide 1 was used as the precursor for the synthesis of a number of new aromatic C-nucleosides containing 1,3,4-oxadiazole 7, [1,3,4]oxadiazolo[2,3-a]isoindole 10b and pyrazole units 18. On the other hand, the thiosemicarbazone 20 was used as the key intermediate for synthesis of 1,3,4-oxadiazole and 1,2,4-triazole-3-thione derivatives 21 and 23.…”

“…A number of nucleoside analogues have been found to show a broad spectrum of biological effects such as antifungal [1,2], antibacterial [1][2][3], antitumor [3][4][5], antiviral [3,4,[6][7][8][9][10][11][12][13][14] anti-inflammatory [15] and analgesic [15] activities. Moreover, 2'-deoxy-2'-fluoro-2'-C-methyl nucleoside analogues have showed promising activity against HCV replication [16].…”

Five‐Membered Heterocycles: 1,2‐Azoles. Part 1. Pyrazoles

“…Oxidations using chlorine in CCl 4 [327], chloranil [164,328], trichloroisocyanuric acid [329], Pd/C in acetic acid [330], DDQ [331] and Bi(NO 3 ) 3 with MW irradiation [332] have been reported.…”