Efficient one-pot synthesis of deoxyfructosazine and fructosazine from D-glucosamine hydrochloride using a basic ionic liquid as a dual solvent-catalyst

An efficient one-pot dehydration process for convert D-glucosamine hydrochloride (GlcNH(2)) into 2-(D-arabino-1',2',3',4'-tetrahydroxybutyl)-5-(D-erythro-2 '',3 '',4 ''-trihydroxybutyl)pyrazine (deoxyfructosazine, DOF) and 2,5-bis-(D-arabino-1,2,3,4-tetrahydroxybutyl)pyrazine (fructosazine, FZ) was reported. A task-specific basic ionic liquid, 1-butyl-3-methylimidazolium hydroxide ([BMIM]OH), was employed as an environmentally-friendly solvent and catalyst. The products were qualitatively and quantitatively characterized by MALDI-TOF-MS, H-1 NMR and C-13 NMR spectroscopy. The influences of GlcNH(2) concentrations, reaction temperature, reaction time, additives and co-solvents on the yields of products were studied. The maximum yield of 49% was obtained in the presence of [BMIM]OH and DMSO under optimized conditions (120 degrees C, 180 min). In addition, a plausible mechanism was proposed. Our project was to develop efficient, atom economical and eco-compatible routes for the synthesis of heterocyclic compounds from marine biomass (or nitrogen-containing biomass). The obtained aromatic heterocyclic compounds showed potential pharmacological action and physiological effects, and they also could be utilized as flavoring agents in the food industry.