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1.
Molecules ; 21(8)2016 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-27556444

RESUMO

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.


Assuntos
Furaldeído/síntese química , Xilanos/química , Xilose/química , Catálise , Polímeros de Fluorcarboneto/química , Furaldeído/química , Temperatura Alta , Micro-Ondas , Estrutura Molecular , Cloreto de Sódio/química , Água/química
2.
Acta Crystallogr Sect E Struct Rep Online ; 69(Pt 6): o954-5, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23795114

RESUMO

The asymmetric unit of the title compound, C15H17N5, consists of two mol-ecules 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 mol-ecules within the asymmetric unit are linked into dimers by pairs of N-H⋯N hydrogen bonds. Weak C-H⋯π contacts and π-π inter-actions [centroid-centroid = 3.3071 (1) Å] further connect the mol-ecules into a three-dimensional network.

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