Pentose dehydration and direct transformation of xylan into furfural were performed in a water-cyclopentyl methyl ether (CPME) biphasic system under microwave irradiation. Heated up between 170 and 190 • C in the presence of Nafion NR50 and NaCl, D-xylose, L-arabinose and xylan gave furfural with maximum yields of 80%, 42% and 55%, respectively. The influence of temperature and reaction time on the reaction kinetics was discussed. This study was also completed by the survey of different reactant ratios, such as organic layer-water or catalyst-inorganic salt ratios. The exchange between proton and cation induced by an excess of NaCl was monitored, and a synergetic effect between the remaining protons and the released HCl was also discovered.

No abstract

The asymmetric unit of the title compound, C15H17N5, consists of two mol­ecules in which the dihedral angles between the best planes of the purine ring system (r.m.s. deviations = 0.0060 and 0.0190 Å) and the benzene ring are 89.21 (3) and 82.14 (4)°. The mol­ecules within the asymmetric unit are linked into dimers by pairs of N—H⋯N hydrogen bonds. Weak C—H⋯π contacts and π–π inter­actions [centroid–centroid = 3.3071 (1) Å] further connect the mol­ecules into a three-dimensional network.