Synthesis and Antibacterial Activity of Some Glucosyl- and Ribosyl-Pyridazin-3-ones

Reaction of 5,6-diphenylpyridazin-3(2H)-one 1a,b with 2,3,4,6-tetra-O-acetyl-D-glucopyranosyl bromide 2 in K2CO3/acetone gave 5,6-diphenyl-N2-(2',3',4',6'-tetra-O-acetyl-D-glucopyranosyl)pyridazin- 3-one 5a,b. The same nucleosides 5a,b were obtained by reaction of 1a,b with peracetylated glucose 3 under MW irradiation. Mercuration of 1a,b followed by reaction with glucosyl bromide 2 gave the same nucleosides 5a,b. The riboside 4-cyano-5,6-diphenyl-N2-(2',3',5'-tri-O-acetyl-D-ribofuranosyl)-pyridaz in-3-one 8 was obtained by reaction of 4-cyanopyridazinone 1b with peracetylated ribose 7 under MW irradiation. The deprotected nucleosides 6a,b and 9 were obtained by stirring of 5a,b and 8 in methanol and TEA/H2O. The structure was confirmed using 1H and 13C-NMR spectra. Selected members of these compounds were screened for antibacterial activity.