scholarly journals Investigation of Friedel-Crafts Alkylation in the Presence of Supported Sulfonic Acid on Silica Gel

2012 ◽  
Vol 9 (4) ◽  
pp. 1875-1884
Author(s):  
A. R. Kiasat ◽  
M. Karimi-Cheshmeali ◽  
R. Soleymani ◽  
H. Rajabzadeh
Keyword(s):  
Sulfuric Acid ◽  
Silica Gel ◽  
Aromatic Compounds ◽  
Sulfonic Acid ◽  
Solid Acid ◽  
Bond Formation ◽  
Reaction Products ◽  
Reaction Progress ◽  
Short Time ◽  
Layer Chromatography

From the Reaction between cellulose and chloro sulfonic acid was prepared sulfuric acid cellulose composition as a new solid acid. The solid acid supported on silica gel and then as an effective catalyst in Friedel-Crafts alkylation of alcohols and aromatic compounds was used. The reaction progress was controlled using thin layer chromatography and the reaction products were analyzed using IR spectroscopy devise. The results show this new catalyst is effective in the friedel crafts alkylation and C-C bond formation was done in short time with very good yields.

Indoxyl Acetate Spray Reagent for Fluorogenic Detection of Cholinesterase Inhibitors in Environmental Samples

1969 ◽  
Vol 52 (1) ◽  
pp. 151-156
Author(s):  
R L Schutzmann ◽  
W F Barthel
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Environmental Samples ◽  
Cholinesterase Inhibitors ◽  
Opposite Polarity ◽  
Cholinesterase Inhibition ◽  
Solvent Mixtures ◽  
Reaction Products ◽  
Layer Chromatography

Abstract A cholinesterase inhibition method to detect ihionophosphates (P=S compounds) and their oxygen analogs (P=O) by twodimensional thin layer chromatography is described. Environmental samples are cleaned up on Florex columns and spotted on silica gel thin layer plates. Plates are developed in solvent mixtures of opposite polarity, then sprayed with an enzyme solution and indoxyl acetate. Submicrogram sensitivity is achieved by fluorogenic and chromogenic reaction. Some compounds give characteristic colored reaction products.

A Preliminary Study of the Carbon-Based Solid Acid Preparation Process

2013 ◽  
Vol 734-737 ◽  
pp. 2236-2239
Author(s):  
Yong Li Li ◽  
Li Ping Mao ◽  
Cai Feng Xu ◽  
Shi You Li
Keyword(s):  
Sulfuric Acid ◽  
Acid Content ◽  
Sulfonic Acid ◽  
Solid Acid ◽  
Acid Group ◽  
Raw Material ◽  
Ftir Analysis ◽  
Solid Carbon ◽  
Activity Temperature ◽  
Preliminary Study

Cotton and sulfuric acid that concentration is 98% as the raw material, to compare the resulting solid carbon sulfonic acid content of the material under different reaction temperatures. FTIR analysis shows that the cotton carbon is an amorphous carbon after sulfonation reactions, a sulfonic acid group present in the resulting material. When the sulfonation temperature is 170 °C, the prepared cotton carbon sulfonic acid has the highest acid content. By the sulfuric acid TG/DTG curve analysis, it verify: 170 °C is the highest activity temperature point of sulfuric acid sulfonation reaction.

scholarly journals Phospho sulfonic acid: A novel and efficient solid acid catalyst for the one-pot preparation of 2H-indazolo[2,1-b]-phthalazine-triones

2013 ◽  
Vol 78 (4) ◽  
pp. 469-476 ◽  
Author(s):  
Reza Kiasat ◽  
Arash Mouradezadegun ◽  
Jafar Saghanezhad
Keyword(s):  
Sulfonic Acid ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Catalytic Amount ◽  
One Pot ◽  
Solvent Free Conditions ◽  
Three Component Reaction ◽  
The One ◽  
Short Time

The efficient one-pot condensation of aldehyde, dimedone, and phthalhydrazide has been achieved in the presence of a catalytic amount of phospho sulfonic acid as a novel environmentally benign heterogeneous solid acid under solvent-free conditions. A diversified 2H-indazolo[1,2-b]phthalazinetrione derivatives were prepared in good to excellent yields in short time. The economical factors (time, cost, waste etc.) for this three-component reaction hold promise for the future of organic synthesis.

scholarly journals Development of Chromatographic Methods for Determination of Agrimoniin and Related Polyphenols in Pharmaceutical Products

2009 ◽  
Vol 92 (2) ◽  
pp. 410-418 ◽  
Author(s):  
Izabela Fecka
Keyword(s):  
Silica Gel ◽  
Extraction Procedure ◽  
Pharmaceutical Products ◽  
Hplc Method ◽  
Mobile Phases ◽  
Sample Extraction ◽  
Unmodified Silica ◽  
Short Time ◽  
Layer Chromatography

Abstract Thin-layer chromatography (TLC) and liquid chromatography (LC) methods were developed for the qualitative and quantitative determination of agrimoniin, pedunculagin, ellagic acid, gallic acid, and catechin in selected herbal medicinal products from Rosaceae: Anserinae herba, Tormentillae rhizoma, Alchemillae herba, Agrimoniae herba, and Fragariae folium. Unmodified silica gel (TLC Si60, HPTLC LiChrospher Si60) and silica gel chemically modified with octadecyl or aminopropyl groups (HPTLC RP18W and HPTLC NH2) were used for TLC. The best resolution and selectivity were achieved with the following mobile phases: diisopropyl etheracetoneformic acidwater (40 30 20 10, v/v/v/v), tetrahydrofuranacetonitrilewater (30 10 60, v/v/v), and acetoneformic acid (60 40, v/v). Concentrations of the studied herbal drugs were determined by using a Chromolith Performance RP-18e column with acetonitrilewaterformic acid as the mobile phase. Determinations of linearity, range, detection and quantitation limits, accuracy, precision, and robustness showed that the HPLC method was sufficiently precise for estimation of the tannins and related polyphenols mentioned above. Investigations of suitable solvent selection, sample extraction procedure, and short-time stability of analytes at storage temperatures of 4 and 20C were also performed. The percentage of agrimoniin in pharmaceutical products was between 0.57 and 3.23.

Benzylation of Aromatic Compounds Catalyzed by 3-Methyl-1-sulfonic Acid Imidazolium Tetrachloroaluminate and Silica Sulfuric Acid under Mild Conditions

Synlett ◽  
2013 ◽  
Vol 24 (09) ◽  
pp. 1113-1116 ◽  
Author(s):  
Mohammad Zolfigol ◽  
Hooshang Vahedi ◽  
Saeid Azimi ◽  
Ahmad Moosavi-Zare
Keyword(s):  
Sulfuric Acid ◽  
Aromatic Compounds ◽  
Sulfonic Acid ◽  
Silica Sulfuric Acid ◽  
Mild Conditions

Application of Thin-layer Chromatography to the Quantitation of Plasma Neutral Lipids and Free Fatty Acids

1967 ◽  
Vol 13 (9) ◽  
pp. 773-787 ◽  
Author(s):  
Robert T Louis-Ferdinand ◽  
Donald G Therriault ◽  
William F Blatt ◽  
Milton Mager ◽  
Edward J Metheson
Keyword(s):  
Fatty Acids ◽  
Sulfuric Acid ◽  
Thin Layer ◽  
Free Fatty Acids ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Neutral Lipids ◽  
Layer Chromatography

Abstract Neutral lipids and free fatty acids were extracted from plasma and separated on thin-layer chromatoplates coated with silica gel G. The plates were charred by heating after spraying with dichromate-sulfuric acid, and then evaluated densitometrically. Plasma analyses obtained by this procedure were compared with parallel determinations performed by established chemical technics.

scholarly journals Potentiation of PBD Dimers by Lipophilicity Manipulation

2019 ◽  
Vol 19 (9) ◽  
pp. 741-752 ◽  
Author(s):  
Thaїs Cailleau ◽  
Lauren R. Adams ◽  
Neha Arora ◽  
Gyoung-Dong Kang ◽  
Luke Masterson ◽  
...  
Keyword(s):  
Silica Gel ◽  
Cathepsin B ◽  
Uv Light ◽  
Flash Chromatography ◽  
Enantiomerically Pure ◽  
Reaction Progress ◽  
Drug Conjugates ◽  
Layer Chromatography

Background & Introduction: Pyrrolobenzodiazepine (PBD) dimers are highly potent DNA cross-linking agents used as warheads in Antibody Drug Conjugates (ADCs) for cancer therapy. We propose to investigate the correlation existing between the lipophilicity of those molecules and their activity (both in vitro and in vivo) as well as any effect observed during conjugation. Materials and Methods: Reaction progress was monitored by Thin-Layer Chromatography (TLC) using Merck Kieselgel 60 F254 silica gel, with a fluorescent indicator on aluminium plates. Visualisation of TLC was achieved with UV light or iodine vapour unless otherwise stated. Flash chromatography was performed using Merck Kieselgel 60 F254 silica gel. Results: We have successfully designed and synthesized a novel PBD warhead (SG3312) with enhanced physicochemical properties. The warhead also displayed increased potency in vitro. After overcoming some epimerization issues, the synthesis of enantiomerically pure payload was achieved (SG3259) and fulfilled our criteria for a simplified and more efficient conjugation. No addition of propylene glycol was required, and high DAR and excellent monomeric purity were achieved. Conclusion: The ADC (Herceptin-maia-SG3259) has been shown to release the active warhead (SG3312) upon exposure to Cathepsin B and demonstrated encouraging activity both in vitro and in vivo.

scholarly journals Pretreatment of Switchgrass for Production of Glucose via Sulfonic Acid-Impregnated Activated Carbon

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 504
Author(s):  
Yane Ansanay ◽  
Praveen Kolar ◽  
Ratna Sharma-Shivappa ◽  
Jay Cheng ◽  
Consuelo Arellano
Keyword(s):  
Activated Carbon ◽  
Sulfonic Acid ◽  
Solid Acid ◽  
Methanesulfonic Acid ◽  
Biofuel Production ◽  
Acid Catalysts ◽  
Effects Of Temperature ◽  
Carbon Catalysts ◽  
Hydrolysis Of

In the present research, activated carbon-supported sulfonic acid catalysts were synthesized and tested as pretreatment agents for the conversion of switchgrass into glucose. The catalysts were synthesized by reacting sulfuric acid, methanesulfonic acid, and p-toluenesulfonic acid with activated carbon. The characterization of catalysts suggested an increase in surface acidities, while surface area and pore volumes decreased because of sulfonation. Batch experiments were performed in 125 mL serum bottles to investigate the effects of temperature (30, 60, and 90 °C), reaction time (90 and 120 min) on the yields of glucose. Enzymatic hydrolysis of pretreated switchgrass using Ctec2 yielded up to 57.13% glucose. Durability tests indicated that sulfonic solid-impregnated carbon catalysts were able to maintain activity even after three cycles. From the results obtained, the solid acid catalysts appear to serve as effective pretreatment agents and can potentially reduce the use of conventional liquid acids and bases in biomass-into-biofuel production.

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