Zur Chemie des Bis(methylsulfonyl)-amins (Dimesylamins), V [1] N-Chlorsulfonyl-methansulfonamid: Ein Produkt der Reaktion von Tetramethylsilan mit Imido-bis(schwefelsäurechlorid) / Investigations on Bis(methylsulphonyl)-amine (Dimesylamine), V [1] N-Chlorosulphonyl-methanesulphonamide: A Reaction Product from Tetramethylsilane and Imido-bis(sulphuryl chloride)

1983 ◽  
Vol 38 (6) ◽  
pp. 793-794 ◽  
Author(s):  
Armand Blaschette ◽  
Gerlinde Seurig
Keyword(s):  
High Yield ◽  
Reaction Conditions ◽  
Product Mixture ◽  
Moisture Sensitive ◽  
Hydrolysis Of ◽  
Complex Manner

AbstractTetramethylsilane reacts with HN(SO2Cl)2 (1) in a complex manner, the nature of the product mixture depending strongly on the reaction conditions. Refluxing 1 with TMS in excess, using CH2Cl2 as a diluent, affords in high yield the new compound HN(SO2Cl)(SO2Me) (2) according to eq. (3). Hydrolysis of the crystal-line, moisture sensitive compound 2 is described by eq. (4).

Biological Conversion of Corncob Residues of Xylose Manufacture to L-Lactic Acid

2011 ◽  
Vol 236-238 ◽  
pp. 330-333 ◽  
Author(s):  
Tian Tian Sun ◽  
Ya Can Zhao ◽  
Jian Wu ◽  
Gui Fu Dai ◽  
Jun Ping Zhu
Keyword(s):  
Lactic Acid ◽  
Enzyme Concentration ◽  
High Yield ◽  
Sodium Acetate Buffer ◽  
Acid Fermentation ◽  
Reaction Conditions ◽  
Biological Conversion ◽  
Percent Conversion ◽  
Main Factors ◽  
Hydrolysis Of

The aim of this research is to study the saccharification of corncob residues of xylose manufacture by enzymes and turn it to L-lactic acid by fermentation. Corncob residues of xylose manufacture is one kind of lignocelluloses composed of 48.5% cellulose, 21.3% lignin, and 23.5% hemicellulose. As one of the most widely used organic acids in industry and the precursor of PLA, a degradable plastic, L-lactic acid is a very important material. In this study, six kinds of cellulases and one kind of β-glucosidase produced by different companies were studied to obtain high yield sugars needed for L-lactic acid fermentation. Results showed that composite of different enzymes could improve the catalysis effects. Mixture of cellulose F3: cellulose F4: β-glucosidase at the ratio of 2:4:9 engendered a high synergistic effect in hydrolysis. Also, the main factors influencing the hydrolysis of corncob residues were investigated. The appropriate reaction conditions are sodium acetate buffer 0.05-0.1mol/L, pH 5.0-5.5, concentration of corncob residues 15%, enzyme concentration 97U for 1g substrate, reaction temperature 50°C and the shaker speed 140 r/min. After 96h reaction, the concentration of glucose could reach as high as 5.5%. In fermentation, 4.48% of L-lactic acid was produced in 24 hours utilizing hydrolysis sugars as the carbon source, and the percent conversion of glucose to L- lactic acid was 81.5%.

scholarly journals Membrane Technology Application for Fractionation Process to Obtain High Quality Glucosamine

REAKTOR ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 103-108
Author(s):  
Nur Rokhati ◽  
Titik Istirokhatun ◽  
Nur ‘Aini Hamada ◽  
Dwi Titik Apriyanti
Keyword(s):  
High Yield ◽  
Permeate Flux ◽  
Absorption Bands ◽  
Reaction Conditions ◽  
Ultrafiltration Membranes ◽  
Fractionation Process ◽  
Technology Application ◽  
Low Molecular Weight Chitosan ◽  
Hydrolysis Of ◽  
Chitosan Hydrolysis

Glucosamine, monosaccharide from chitosan obtained from the chitin deacetylation process, has been used widely in various fields such as nutrition, pharmacy, and cosmetics. Glucosamine can be obtained from the hydrolysis of chitosan. Enzymatic hydrolysis provides the advantage of mild reaction conditions, environmentally friendly, and high yield. But until now, the separation of glucosamine from the chitosan hydrolysis fraction has been an obstacle. Ultrafiltration membranes offer an efficient filtration process because they do not require additional chemicals. The performance of ultrafiltration membranes was analyzed from the fractionation process of chitosan hydrolysis. The PES membranes in 10, 25, and 50 kDa were used to filter hydrolyzed Low Molecular Weight Chitosan (LMWC) in varied concentrations. The experiment was carried out in crossflow membrane module for flat sheet at room temperature in 1 bar. The permeate flux during filtration decreased rapidly at the initial and gradually over time because of fouling and concentration polarization. The more concentrated hydrolyzed LMWC solution resulted higher percentage of rejection up to almost 20% at the same membrane MWCO while higher MWCO resulted lower rejection percentage for the same hydrolyzed LMWC concentration. The FTIR spectrum of the used membranes of all types had absorption bands of glucosamine which proved that the fractionation process occurred. The time retention in HPLC chromatograms of glucosamine produced were similar with standard glucosamine. Thus, ultrafiltration could be applied for hydrolyzed LMWC fractionation process.Keywords: fractionation; glucosamine; LMWC; MWCO; ultrafiltration

Gold Catalyzed Hydroamination of Propargylic Alcohols: Controlling Divergent Reaction Pathways to Access 1,3-Aminoalcohols, 3-Hydroxyketones or 3-Aminoketones

2018 ◽  
Author(s):  
Victor Laserna ◽  
Tom Sheppard
Keyword(s):  
Gold Catalysis ◽  
Reaction Pathways ◽  
High Yield ◽  
Reaction Conditions ◽  
Propargylic Alcohols ◽  
Catalytic Quantity ◽  
Selective Formation ◽  
General Method

A versatile approach to the valorization of propargylic alcohols is reported, enabling controlled access to three different products from the same starting materials. Firstly, a general method for the hydroamination of propargylic alcohols with anilines is described using gold catalysis to give 3-hydroxy imines with complete regioselectivity. These 3-hydroxyimines can be reduced to give 1,3-aminoalcohols with high syn seletivity. Alternatively, by using a catalytic quantity of aniline, 3-hydroxyketones can be obtained in high yield directly from propargylic alcohols. Further manipulation of the reaction conditions enables the selective formation of 3-aminoketones via a rearrangement/hydroamination pathway.<br>

Addition of Tetrachloromethane to 1,5-Hexadiene

1992 ◽  
Vol 57 (2) ◽  
pp. 393-396 ◽  
Author(s):  
Martin Kotora ◽  
Milan Hájek
Keyword(s):  
Palladium Catalyst ◽  
Adduct Formation ◽  
High Yield ◽  
Reaction Conditions ◽  
Dibenzoyl Peroxide

The 2 : 1 adduct as the final product of the addition of tetrachloromethane to 1,5-hexadiene catalyzed by copper(I)-butylamine complex was obtained in high yield (96%) under mild reaction conditions. Predominant 1 : 1 adduct formation was observed in the presence of a palladium catalyst or dibenzoyl peroxide initiator.

Process intensification for enzyme assisted turmeric starch hydrolysis in hydrotropic and supercritical conditions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yogita P. Labrath ◽  
Prafulla V. Belge ◽  
Uma G. Kulkarni ◽  
Vilas G. Gaikar
Keyword(s):  
Residence Time ◽  
Filtration Rate ◽  
Room Temperature ◽  
Curcuma Longa ◽  
Process Intensification ◽  
Enzyme Treatment ◽  
Starch Hydrolysis ◽  
Reaction Conditions ◽  
Natural Form ◽  
Hydrolysis Of

Abstract The turmeric rhizome (Curcuma longa) contains curcuminoids embedded in the starch matrix. It is thus important to target starch hydrolysis to enhance extraction of curcuminoids. In the case of starch hydrolysis, α-amylase is more efficient when the starch is in a gelatinised form than when it is in its natural form. The present work includes hydrolysis of turmeric starch in its natural and gelatinised forms using α-amylase in hydrotrope solution (HS) and scCO2. The optimum rate of starch hydrolysis was obtained using 200 IU cm−3 of α-amylase, at reaction conditions of 6.5 pH at 328 K when 10% w/w of turmeric powder was stirred at 900 rpm in HSs. The hydrolysis in 15 MPa scCO2 at room temperature required a phase modifier and 40 min of residence time (RT). The enzyme treatment of turmeric powder in HSs increased the filtration rate for curcuminoid extraction (gelatinised and native) compared to untreated turmeric powder.

Chemoselective Double Michael Addition: Synthesis of 2,6-Diarylspiro[Cyclohexane-1,3′-Indoline]-2′,4-Diones via Addition of Indolin-2-One to Divinyl Ketones

2017 ◽  
Vol 41 (3) ◽  
pp. 168-171 ◽  
Author(s):  
Zheng Li ◽  
Jiasheng Li ◽  
Jingya Yang
Keyword(s):  
Michael Addition ◽  
High Yield ◽  
Reaction Conditions ◽  
Michael Additions

Seventeen examples of 2,6-diarylspiro[cyclohexane-1,3′-indoline]-2′4-diones were efficiently prepared by the Cs2CO3-catalysed chemoselective double Michael additions of indolin-2-one to divinyl ketones. This method has the advantage of high chemoselectivity, mild reaction conditions, high yield and atom- and step-economy.

Cleavage of C=N derivatives and Oxidation of Thiols in Water under Neutral Conditions with 1,4-dichloro-1,4-diazoniabicyclo[2,2,2]octane bischloride

2007 ◽  
Vol 2007 (8) ◽  
pp. 486-489 ◽  
Author(s):  
Mahmood Tajbakhsh ◽  
Setareh Habibzadeh
Keyword(s):  
Carbonyl Compounds ◽  
High Yield ◽  
Reaction Conditions ◽  
Neutral Conditions

1,4-Diazabicyclo[2,2,2]octane (DABCO) is easily chlorinated and gives a complex which efficiently converts aliphatic and aromatic oximes, phenylhydrazones and semicarbazones to their corresponding carbonyl compounds in water at 50°C in high yield. This reagent can also be used for conversion of thiols to their compounding disulfide under the same reaction conditions. DABCO is quantitatively recovered which can be rechlorinated and reused several times.

Regiospecific preparation of 10-allyl-1-ketoquinolizidine and an unexpected disproportionation during its Wolff–Kischner reduction

1979 ◽  
Vol 57 (16) ◽  
pp. 2114-2117 ◽  
Author(s):  
John M. McIntosh
Keyword(s):  
Ring System ◽  
Sigmatropic Rearrangement ◽  
High Yield ◽  
Reaction Conditions ◽  
Fused Ring ◽  
Fused Ring System

Regiospecific formation of 10-allyl-1-ketoquinolizidine (7) is achieved in high yield by a [2.3] sigmatropic rearrangement of N-allyl-1-ketoquinolizidinium bromide (6). Wolff–Kischner reduction of 7 affords 10-allylquinolizidine (8) contaminated by the 10-propyl and 10-ethynyl analogs in amounts which depend on the reaction conditions. The carbon-13 spectrum of 8 indicates a trans-fused ring system with an axial substituent at C-10.

scholarly journals Preparation of Glucosamine Hydrochloride from Indigenous Shrimp Processing Waste

1970 ◽  
Vol 46 (3) ◽  
pp. 375-378 ◽  
Author(s):  
MM Islam ◽  
SM Masum ◽  
MM Rahman ◽  
AA Shaikh
Keyword(s):  
Maximum Yield ◽  
Therapeutic Activity ◽  
Processing Waste ◽  
Reaction Conditions ◽  
Glucosamine Hydrochloride ◽  
Glycoside Linkage ◽  
Shrimp Shell ◽  
Reaction Proceeds ◽  
Ft Ir ◽  
Hydrolysis Of

The present investigation described the effective preparation of glucosamine hydrochloride (GluHCl) from chitin which was extracted from indigenous shrimp shell. GluHCl has attracted much attention owing to its therapeutic activity in osteoarthritis and widely used dietary supplement. The key step involved was extraction of chitin from shrimp skeleton and then hydrolysis of chitin by concentrated hydrochloric acid. The reaction proceeds via break down of glycoside linkage. Structural analysis was carried out by melting point, TLC, FT-IR, elemental analysis and all the data were compared with that of standard GluHCl. The elemental (C, 32.75; H, 6.51; N, 6.20) analysis is good concord with the calculated value (C, 33.42; H, 6.54; N, 6.50). Absence of v max at 1726 cm-1 indicates that GluHCl is a deacetylated product of chitin. The yields of the product mainly depend on reaction conditions. Maximum yield (63.5%) was obtained when chitin was hydrolyzed with concentrated HCl for 1.30 h. Key words: Shrimp shell; Chitin, Acid hydrolysis; Glucosamine hydrochloride Osteoarthritis. DOI: http://dx.doi.org/10.3329/bjsir.v46i3.9046 BJSIR 2011; 46(3): 375-378

scholarly journals Isolation of Free Amino Acids via Enzymatic Hydrolysis of Tobacco-Derived F1 Protein

2018 ◽  
Vol 28 (4) ◽  
pp. 179-190
Author(s):  
Mehdi Ashraf-Khorassani ◽  
William M. Coleman ◽  
Michael F. Dube ◽  
Larry T. Taylor
Keyword(s):  
Amino Acids ◽  
Enzymatic Hydrolysis ◽  
Free Amino Acids ◽  
Free Amino ◽  
Protein Concentration ◽  
Enzyme Concentration ◽  
Enzymatic Conversion ◽  
Reaction Conditions ◽  
Analytical Methodology ◽  
Hydrolysis Of

SummaryFree amino acids have been isolated via optimized enzymatic hydrolysis of F1 tobacco protein using two cationic resins (Amberlite IR120 and Dowex MAC-2). Optimized enzymatic conversions of the protein as a result of systematic variations in conditions (e.g., time, temperature, pH, enzyme type, enzyme concentration, anaerobic/aerobic environments, and protein concentration) employing commercially available enzymes, were consistently higher than 50% with qualitative amino acid arrays that were consistent with the known composition of tobacco F1 protein. Amberlite IR120 was shown to have a much higher efficiency and capacity for isolation of amino acids from standard solutions and from hydrolysate when compared with the results using Dowex MAC-2. Two columns packed with conditioned Amberlite IR120 (120 × 10 mm,12–15 g resin) and (200 × 25.4 mm, 60–65 g resin) were used to isolate two batches (2.5–3.0 mg and 13–15 mg) of free amino acids, respectively. A relatively inexpensive analytical methodology was developed for rapid analysis of the free amino acids contained within the enzyme hydrolysate. Commercially available enzymes, when employed in optimized reaction conditions, are very effective for enzymatic conversion of tobacco F1 protein to free amino acids.

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