Synthesis of double headed imidazoline acyclo C-nucleosides: 1,4-bis[1-amino-5-oxo-4-substituted(imidazolin-2-yl)]galacto-tetritols.
Condensation of 2,3,4,5-tetra-O-acetyl-galactaroyl dichloride (1) with two equivalents of the alpha-amino esters 2a-c gave the corresponding 2,3,4,5-tetra-O-acetyl-galactaric acid diamides 3a-c. Heterocyclization of 3a-c by heating with hydrazine hydrate took place with concomitant de-O-acetylation of the polyacetoxyalkyl chain to give 1,4-bis[1-amino-5-oxo-4-substituted(imidazolin-2-yl)] galacto-tetritols (5a-c) and not the theoretically possible 1,2,4-triazinones 4 as indicated by spectral data. Compounds 5a-c readily reacted with p-nitrobenzaldehyde to give the corresponding p-nitrobenzylideneamino derivatives 6a-c. Acetylation of 5a-c afforded the 2,3,4,5-tetra-O-acetyl-1,4-bis[1-acetamido-5-oxo-4-substituted(imidazolin-2-yl)]galacto-tetritols (7a,b,d). De-O-acetylation of 7a,b,d gave 1,4-bis[1-acetamido-5-oxo-4-substituted (imidazolin-2-yl)]galacto-tetritols (8a-c).
Nasr
Adel Z
AZ
Department of Chemistry, Faculty of Science, Cairo University, Faiyoum, Egypt. Adelnasr@hotmail.com
D007093:Imidazoles / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013780:Tetroses / Q000138:chemical synthesis* / Q000737:chemistry
D007093:Imidazoles; D009705:Nucleosides; D013780:Tetroses; C002053:tetritol