Microwave-assisted organic synthesis of 3-(D-Gluco-pentitol-1-yl)-1H-1,2,4-triazole.

The condensation of D-glucono- and D-galactono-1,5-lactone and thiocarbohydrazide to give 3-(D-alditol-1-yl)-4-amino-5-mercapto-1,2,4-triazoles 4 and 5 is accelerated by the use of microwave-assisted organic reaction (MAOS). The deamination and dethiolation of compound 4 to give 6 was also accelerated by the use of MAOS. Condensation of 4 and 5 with p-nitrobenzaldehyde afforded Schiff bases 8 and 9, respectively, within 4 min under microwave irradiation (MWI), whereas with ethyl chloroacetate the thioalkylated products 14 and 15 were obtained in 8 min. The structures of the synthesized compounds were confirmed by 1H NMR, 2D NMR, and mass spectra.