An Efficient Way to the Synthesis of 2-Deoxy-2-[(7-nitro-2,1,3- benzoxadiazol-4-yl)amino]-β-D-glucopyranose (2-NBDG) via 7-Nitro-2,1,3- benzoxadiazol-4-yl Chloride (NBD-Cl)

The fluorescent D-glucose derivative, 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-β-Dglucopyranose (2-NBDG) is synthesized by reacting D-glucosamine with inexpensive 7-nitro-2,1,3-benzoxadiazol-4-yl chloride (NBD-Cl). A series of reaction conditions such as reaction time, bases, the loading of bases, solvents and reaction temperature has been investigated. The yield of 2-NBDG can be enhanced to 83.0% under the optimal reaction conditions. Meanwhile, a gram-scale synthesis of 2-NBDG was also realized with 80.0% isolated yield.