An integrated process for the production of platform chemicals and diesel miscible fuels by acid-catalyzed hydrolysis and downstream upgrading of the acid hydrolysis residues with thermal and catalytic pyrolysis

2012 ◽  
Vol 126 ◽  
pp. 92-100 ◽  
Author(s):  
Buana Girisuta ◽  
Konstantinos G. Kalogiannis ◽  
Karla Dussan ◽  
James J. Leahy ◽  
Michael H.B. Hayes ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Catalytic Pyrolysis ◽  
Integrated Process ◽  
Platform Chemicals ◽  
Acid Catalyzed

Preparation of conjugates of uridine with proteins by the imido ester condensation method

1981 ◽  
Vol 46 (4) ◽  
pp. 933-940 ◽  
Author(s):  
Helmut Pischel ◽  
Antonín Holý ◽  
Günther Wagner
Keyword(s):  
Human Serum ◽  
Acid Hydrolysis ◽  
Ester Hydrochloride ◽  
Protein Conjugates ◽  
Condensation Method ◽  
Ester Condensation ◽  
Acid Catalyzed

Reaction of 5'-O-p-toluenesulfonyl-2',3'-O-isopropylideneuridine (I) with sodium 4-cyanophenoxide afforded 2',3'-O-isopropylidene-5'-O-(4-cyanophenyl)uridine (II) which was converted by acid hydrolysis into 5'-O-(4-cyanophenyl)uridine (IIIa). Acid-catalyzed addition of ethanol to compound IIIa gave the imido ester hydrochloride IIIb which on reaction with ammonia or ethylamine was transformed into the amidine derivatives IIIc and IIId. Compound IIIb reacted with human serum albumine or bovine gamma-globuline at pH 9.2 to give protein conjugates with uridine, bound covalently by an amidine bond (IIIe,f).

THE ACID HYDROLYSIS OF GLYCOSIDES: I. GENERAL CONDITIONS AND THE EFFECT OF THE NATURE OF THE AGLYCONE

1964 ◽  
Vol 42 (6) ◽  
pp. 1456-1472 ◽  
Author(s):  
T. E. Timell
Keyword(s):  
Acid Hydrolysis ◽  
Equilibrium Concentration ◽  
Rate Coefficients ◽  
Acidity Function ◽  
Tertiary Alcohols ◽  
Conjugate Acid ◽  
Rate Of Hydrolysis ◽  
Acid Catalyzed ◽  
Opposing Effects ◽  
Hydrolysis Of

First-order rate coefficients and energies and entropies of activation have been determined for the acid-catalyzed hydrolysis of a number of methyl D-glycopyranosides and disaccharides. The relation between the logarithm of the rate coefficients and values for Hammett's acidity function was linear, although different for different acids. All compounds had entropies of activation indicating a unimolecular reaction mechanism. Glucosides of tertiary alcohols were hydrolyzed very rapidly, triethylmethyl β-D-glucopyranoside, for example, 30,000 times taster than the corresponding methyl compound.Increase in size of the aglycone caused a slight increase in the rate of hydrolysis of β-D-glucopyranosides, steric hindrance thus being of no significance. Electron-attracting substituents in the aglycone had little or no influence on the rate of hydrolysis, obviously because they would tend to lower the equilibrium concentration of the conjugate acid, while facilitating the subsequent heterolysis, the two opposing effects more or less cancelling out. These results were discussed in connection with recent studies on the acid hydrolysis of various phenyl glycopyranosides and with reference to the postulated occurrence of an activating inductive effect in oligo- and poly-saccharides containing carboxyl or other electronegative groups at C-5. It was concluded that there is little evidence for the existence of any such effect and that, for example, pseudoaldobiouronic acids should be hydrolyzed at the same rate as corresponding neutral disaccharides.

Synthesis of 3-amino- and 3-azidoanalogs of 9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA)

1989 ◽  
Vol 54 (2) ◽  
pp. 446-454 ◽  
Author(s):  
Antonín Holý
Keyword(s):  
Acid Hydrolysis ◽  
Sodium Salt ◽  
Catalytic Hydrogenation ◽  
Alkaline Hydrolysis ◽  
Benzoyl Chloride ◽  
Sodium Hydride ◽  
Acid Catalyzed ◽  
Excess Sodium ◽  
Chloride Treatment

1-Azidopropane-2,3-diol (IIb) reacts with p-toluenesulfonyl chloride to give the tosyl derivative IIIa which, on acid catalyzed condensation with 2,3-dihydropyran, afforded 1-azido-2-(tetrahydropyran-2-yloxy-3-(p-toluenesulfonyloxy)propane (IIIb). Treatment of adenine sodium salt with IIIb resulted in the intermediate IV which was transformed by acid hydrolysis to 9-(RS)-(3-azido-2-hydroxypropyl)adenine (V). Catalytic hydrogenation of V led to 9-(RS)-(3-amino-2-hydroxypropyl)adenine (VI). 9-(RS)-(3-Azido-2-hydroxypropyl)-N6-benzoyladenine (VII) was obtained from V by chlorotrimethylsilane/benzoyl chloride treatment. Reaction of the compound VII with dimethyl p-toluenesulfonyloxymethanephosphonate (VIII) in the presence of excess sodium hydride, followed by alkaline hydrolysis, afforded methyl 9-(3-azido-2-phosphonylmethoxypropyl)adenine (IXa) which was transformed to the parent acid IXb by bromotrimethylsilane treatment. Hydrogenolysis of IXb yielded 9-(RS)-(3-amino-2-phosphonylmethoxypropyl)adenine (X).

Acid-catalyzed conversion of mono- and poly-sugars into platform chemicals: Effects of molecular structure of sugar substrate

2013 ◽  
Vol 133 ◽  
pp. 469-474 ◽  
Author(s):  
Xun Hu ◽  
Liping Wu ◽  
Yi Wang ◽  
Yao Song ◽  
Daniel Mourant ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Platform Chemicals ◽  
Acid Catalyzed

Synthesis and Acid-Catalyzed Hydrolysis of Some 3-(4-Methoxyphenyl)propyl Glucuronates

2000 ◽  
Vol 65 (10) ◽  
pp. 1609-1618 ◽  
Author(s):  
Monika Poláková ◽  
Dušan Joniak ◽  
Miloslav Ďuriš
Keyword(s):  
Acid Hydrolysis ◽  
Acid Catalyzed ◽  
Model Substances ◽  
Hydrolysis Of

3-(4-Methoxyphenyl)propyl D-glucuronate, 3-(4-methoxyphenyl)propyl methyl 4-O-methyl-α-Dglucopyranosiduronate, 3-(4-methoxyphenyl)propyl 1,2,3,4-tetra-O-acetyl-α-D-glucopyranuronate and 3-(4-methoxyphenyl)propyl 1,2-(S):3,5-di-O-benzylidene-α-D-glucofuranuronate were prepared as a model substances for the ester lignin-saccharide bonds. Rates of acid-catalyzed hydrolysis of the prepared compounds in 1 M HCl in acetonitrile-water 3 : 1 at 20 °C have been measured by LC-DAD analysis and it showed the low stability of the ester bonds towards acid hydrolysis.

scholarly journals Efficient conversion of glucosamine to levulinic acid in a sulfamic acid-catalyzed hydrothermal reaction

RSC Advances ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 3198-3205 ◽  
Author(s):  
Hyo Seon Kim ◽  
Sung-Koo Kim ◽  
Gwi-Taek Jeong
Keyword(s):  
Levulinic Acid ◽  
Active Sites ◽  
Hydrothermal Reaction ◽  
Sulfamic Acid ◽  
Efficient Conversion ◽  
Platform Chemicals ◽  
Acid Catalyzed

Glucosamine, which is a monomer of chitosan, and sulfamic acid, which has dual active sites, were employed as substrate and catalyst, respectively, to produce the bio-based platform chemicals LA and 5-HMF.

scholarly journals Kinetics and Chemorheological Analysis of Cross-Linking Reactions in Humins

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1804 ◽  
Author(s):  
Sangregorio ◽  
Guigo ◽  
Jong ◽  
Sbirrazzuoli
Keyword(s):  
Complex Viscosity ◽  
Isoconversional Method ◽  
Effect Of Temperature ◽  
Diffusion Control ◽  
Model Free ◽  
Platform Chemicals ◽  
Model Free Kinetics ◽  
Acid Catalyzed ◽  
Advanced Isoconversional Method ◽  
Kinetics Of

Humins is a biomass-derived material, co-product of the acid-catalyzed conversion of cellulose and hemicellulose to platform chemicals. This work presents a thorough study concerning the crosslinking kinetics of humins by chemorheological analysis and model-free kinetics under isothermal and non-isothermal curing. Humins can auto-crosslink under the effect of temperature, and the reaction can be fastener when adding an acidic initiator. Thus, the effect of P-Toluenesulfonic acid monohydrate (pTSA) on the crosslinking kinetics was also studied. The dependencies of the effective activation energy (Eα-dependencies) were determined by an advanced isoconversional method and correlated with the variation of complex viscosity during curing. It is shown that humins curing involves multi-step complex reactions and that the use of an acidic initiator allows faster crosslinking at lower temperatures, involving lower Eα. The shift from chemical to diffusion control was also estimated.

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