Faculty Publications
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Item Hydrochloric acid-catalyzed coproduction of furfural and 5-(chloromethyl)furfural assisted by a phase transfer catalyst(Elsevier Ltd, 2020) Bhat, N.S.; Vinod, N.; Onkarappa, S.B.; Dutta, S.Furfural has been produced in 53% isolated yield from D-xylose within an aqueous HCl-1,2-dichloroethane biphasic reaction mixture using benzyltributylammonium chloride (BTBAC) as a phase transfer catalyst. The use of BTBAC noticeably improved the yield of furfural compared to that in the control reaction. The reaction was optimized on the reaction temperature, duration, concentration of HCl, and the loading of BTBAC. Furfural and 5-(chloromethyl)furfural (CMF) have also been coproduced from a mixture of pentose and hexose sugars. Under optimized conditions (100 °C, 3 h, 20.2% HCl, 10 wt% BTBAC), CMF and furfural were isolated in 17% and 53% yield, respectively, from a mixture of glucose and xylose. In addition, levulinic acid was isolated from the aqueous layer in 31% yield. © 2020 Elsevier LtdItem Preparation of alkyl levulinates from biomass-derived 5-(halomethyl)furfural (X = Cl, Br), furfuryl alcohol, and angelica lactone using silica-supported perchloric acid as a heterogeneous acid catalyst(Springer Science and Business Media Deutschland GmbH, 2020) Onkarappa, S.B.; Bhat, N.S.; Dutta, S.This work reports the synthesis of a series of alkyl levulinates from biomass-derived 5-(halomethyl)furfural (X = Cl, Br), furfuryl alcohol, and angelica lactone using silica-supported perchloric acid (HClO4-SiO2) as a heterogeneous acid catalyst. The solvent-free, one-pot preparation afforded levulinate esters in excellent isolated yields (> 84%). The reactions were performed at 120 °C for 6 h in a batch-type glass pressure reactor using XMF and furfuryl alcohol in presence of excess of the alcohol reagent and 4 wt.% of the HClO4-SiO2 catalyst (0.028 mmol HClO4). Furthermore, the reaction protocol was extended for the synthesis of ALs starting with angelica lactone at 90 °C for 2 h in a round-bottomed flask by using excess alcohol and 4 wt.% of the HClO4-SiO2 catalyst. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.Item Efficient Synthesis of 5‑(Hydroxymethyl)furfural Esters from Polymeric Carbohydrates Using 5‑(Chloromethyl)furfural as a Reactive Intermediate(American Chemical Society, 2022) Bhat, N.S.; Hegde, S.L.; Dutta, S.; Sudarsanam, P.This work reports an efficient, gram-scale synthesis of 5-(hydroxymethyl)furfural (HMF) esters using biomass-derived 5-(chloromethyl)furfural (CMF) as a reactive intermediate. The HMF-esters have potential applications as chemical intermediates, fuel additives, and bioactive compounds. Initially, CMF was prepared in good yields directly from polymeric carbohydrates (starch, inulin, and cellulose) and cellulosic materials (cotton and filter paper) using a biphasic batch reaction system, consisting of aqueous hydrochloric acid and 1,2-dichloroethane. The use of ZnCl2 as an additive allowed the reaction to proceed under milder conditions while significantly improving the isolated yield of CMF. The effects of reaction temperature, reaction time, extracting solvent, and ZnCl2 loading on CMF yield were investigated. Microcrystalline cellulose was converted into CMF with a 72% isolated yield under optimized reaction conditions (80 °C, 2 h). After that, CMF was transformed into various novel esters of HMF in excellent isolated yields (>85%) by reacting with a slight excess amount of the triethylammonium salt of various alkyl/aryl carboxylic acids under solvent-free conditions. © 2022 American Chemical Society.Item Efficient preparation of hybrid biofuels from biomass-derived 5-(acetoxymethyl)furfural and petroleum-derived aromatic hydrocarbons(Royal Society of Chemistry, 2024) Yadav, A.K.; Bhat, N.S.; Kaushik, S.; Seikh, A.H.; Dutta, S.Fuel candidates containing both petroleum-derived and biomass-derived molecules in their structural motifs ensure both feedstocks are used optimally and coherently. This work reports a straightforward and efficient preparation of 5-(arylmethyl)furfurals (AMFFs), 2-(arylmethyl)furans (AMFs), and 2-(arylmethyl)-5-methylfurans (AMMFs) as hybrid biofuels (or fuel oxygenates) starting from carbohydrate-derived 5-(acetoxymethyl)furfural (AcMF) and petroleum-derived aromatic hydrocarbons. The AMFFs were prepared by Friedel-Crafts reaction between AcMF and aromatic hydrocarbons (e.g., BTX, mesitylene) by employing anhydrous ZnCl2 as the catalyst. AMFs were prepared by decarbonylation of AMFFs over the Pd(OAc)2 catalyst under solvent-free conditions. In contrast, AMMFs were produced by hydrogenating AMFFs in methanol using gaseous hydrogen and the 10% Pd/C catalyst. The catalytic transformations were optimized on various parameters, and all the biofuel candidates were obtained in good to excellent isolated yields (>80%) under moderate conditions. © 2024 The Royal Society of Chemistry.Item One-pot production of 5-(chloromethyl)furfural and levulinic acid from marine carbohydrates(Springer Science and Business Media Deutschland GmbH, 2025) C, P.N.; Yadav, A.K.; Aranha, D.A.; Dutta, S.5-(Chloromethyl)furfural (CMF) and levulinic acid (LA) were produced from marine biomass-derived carrageenan (? and ?) and chitin. CMF was produced in HCl (aq., 35%)-1,2-dichloroethane biphasic reaction within a batch-type glass pressure reactor, whereas LA was produced in the same setup using aqueous HCl (20%) only. The reactions were optimized on temperature, duration, stirring speed, volume of solvent, and feedstock loading. The isolated yield of CMF reached 37.8% starting from ?-carrageenan (80 °C, 2 h), whereas chitin afforded a 21.8% yield of CMF (100 °C, 4 h). LA was obtained in a 52.3% yield from ?-carrageenan (120 °C, 4 h) and 36% from chitin (150 °C, 4 h). The mixture of CMF and LA was then converted into HMF-levulinate, a prospective fuel oxygenate, in a one-pot process, affording a 77.8% isolated yield. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.