Ananda S. Amarasekara

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The anomeric composition of d-fructose in dimethyl sulfoxide changes when the solution is heated from room temperature to 150 degrees C, with a small increase in the alpha-furanose form at the expense of the beta-pyranose tautomer. Additionally, a small amount of alpha-pyranose form was also observed at 150 degrees C. A mechanism is proposed for the(More)
Catalytic activities of eight sulfonic acid group functionalized ionic liquids in water were compared for the hydrolysis of Sigmacell cellulose (DP ~ 450) in the 150-180°C temperature range by measuring total reducing sugar (TRS) and glucose produced. The catalytic activity of acidic ionic liquids with different cation types decreases in the order(More)
Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review.(More)
Cellulose can be converted to a mixture of ethyl levulinate and levulinic acid by heating with a Brönsted acidic ionic liquid catalyst in aqueous ethanol medium in a one-pot operation under mild conditions. The highest ethyl levulinate yield of 19.0 % was obtained for a reaction carried out at 170 °C for 12 h in water-ethanol medium containing 38.5 % water(More)
The syntheses of dimethyl 2,2'-bithiophene-4,4'-dicarboxylate (3), dimethyl 2,2'-bithiophene-3,4'-dicarboxylate (4), and dimethyl 2,2'-bithiophene-3,3'-dicarboxylate (5) are described. Single-crystal X-ray structural analysis of these compounds shows that the thiophene rings in 3 and 4 are nearly coplanar (dihedral angle close to 0 degrees ) and they adopt(More)
The effect of ZnCl(2) on the degradation of cellulose was studied to develop conditions to produce useful feedstock chemicals directly from cellulosic biomass. Cellulose containing 0.5 mol of ZnCl(2)/mol of glucose unit of cellulose was found to degrade at 200 degrees C when heated for more than 60 s in air. The major non-gaseous products of the degradation(More)
[reaction: see text] Oxidation of phthalahydrazide (1) with lead tetraacetate in the presence of furfural (3a) in methylene chloride gives [5,6]benza-3a,7a-diaza-3-carboxylindane-4,7-dione-1-ene (7a) in 64% yield. 5-Methylfurfural (3b) also reacted similarly to give the product 7b in 46% yield. Reaction of phathalazine-1,4-dione with(More)
Switchgrass biomass samples collected at three different stages of maturity were seen degrading into reducing sugars and glucose when exposed to 1-(alkylsulfonic)-3-methylimidazolium Brönsted acidic ionic liquids under thermal and microwave conditions. The highest reducing sugar (58.1 ± 2.1 %) and glucose (15.3 ± 0.5 %) yields were obtained for switchgrass(More)
The conversion of D-glucose to 5-hydroxymethylfurfural (HMF) in the presence of 5.48 mol% 1-(1-propylsulfonic)-3-methylimidazolium chloride acidic ionic liquid catalyst in DMSO at 150°C was studied using (1)H, (13)C NMR, and visible spectroscopy. The HMF yield rapidly increases in the first 100 min of reaction, however yield drops beyond 100 min and levels(More)
The interactions of cellulose model compound d-cellobiose with chloride salts of Zn(2+), Ca(2+), Li(+), Sn(2+), La(3+), Mg(2+), K(+) and NH4(+) were evaluated by measuring the (13)C NMR chemical shift changes (Δδ) of the disaccharide due to the addition of salts in D2O. The KCl and NH4Cl showed similar Δδ changes due to interactions only with the Cl(-)(More)