Synthesis and Biological Evaluation of 2-Oxo/Thioxoquinoxaline and 2-Oxo/Thioxoquinoxaline-Based Nucleoside Analogues.

Several O- and S-quinoxaline glycosides have been prepared by glycosidation of 3-methyl-2-oxo(thioxo)-1,2-dihydroquinoxalines 1a,b with α-D-glucopyranosyl, α-D-galactopyranosyl, and α-D-lactosyl bromide in the presence of K2CO3 followed by deacetylation with Et3N/H2O. Furthermore, alkylation of 1a,b with 4-bromobutyl acetate, 2-acetoxyethoxymethyl bromide, and 3-chloropropanol afforded the corresponding O- and S-acycloquinoxaline nucleosides. Reaction of 1b with chloroacetic acid followed by condensation with sulfacetamide and sulfadiazine in the presence of Et3N/THF and ethyl chloroformate gave the corresponding sulfonamide derivatives 14 and 15, respectively.

Synthesis and biological activity of some nucleoside analogs of hydroquinoline-3-carbonitrile.

Hydroquinoline acyclonucleosides 2, 4, 6a,b, 8a,b, 9a,b, and their corresponding N-alkyl derivatives (10-12) were obtained by the reaction of 1a,b with acetoxybutylbromide, (2-acetoxyethoxy)methyl bromide, 3-chloropropanol, 1,3-dichloro-2-propanol, epichlorohydrin, propargyl/allyl bromides in the presence of K(2)CO(3) in dry dimethylformamide (DMF). In a similar manner, reaction of 1a,b with glycosyl/galactosyl and lactosyl bromide afforded the corresponding N-nucloside derivatives 13a,b, 15a,b, and 17, respectively. Deacetylation of the N-nucleosides derivatives in the presence of Et(3)N/MeOH and few drops of water gave the deprotected derivatives 3, 5, 7a,b, 14a,b, 16a,b, and 18 in good yields, respectively.