scholarly journals Utilization of fluoroform for difluoromethylation in continuous flow: a concise synthesis of α-difluoromethyl-amino acids

2018 ◽  
Vol 20 (1) ◽  
pp. 108-112 ◽  
Author(s):  
Manuel Köckinger ◽  
Tanja Ciaglia ◽  
Michael Bersier ◽  
Paul Hanselmann ◽  
Bernhard Gutmann ◽  
...  
Keyword(s):  
Amino Acids ◽  
Continuous Flow ◽  
Waste Product ◽  
Efficient Reagent

Difluoromethylated esters, malonates and amino acids (including the drug eflornithine) are obtained by a gas–liquid continuous flow protocol employing the abundant waste product fluoroform as an atom-efficient reagent.

scholarly journals Enantiomerically Puretrans-β-Lactams from α-Amino Acids via Compact Fluorescent Light (CFL) Continuous-Flow Photolysis

2010 ◽  
Vol 132 (32) ◽  
pp. 11379-11385 ◽  
Author(s):  
Yvette S. Mimieux Vaske ◽  
Maximillian E. Mahoney ◽  
Joseph P. Konopelski ◽  
David L. Rogow ◽  
William J. McDonald
Keyword(s):  
Amino Acids ◽  
Continuous Flow ◽  
Fluorescent Light

scholarly journals Sustainable Electrochemical Decarboxylative Acetoxylation of Aminoacids in Batch and Continuous Flow

2021 ◽  
Author(s):  
Manuel Köckinger ◽  
Paul Hanselmann ◽  
Dominique M. Roberge ◽  
Pierro Geotti-Bianchini ◽  
C. Oliver Kappe ◽  
...  
Keyword(s):  
Amino Acids ◽  
Continuous Flow ◽  
Flow Mode ◽  
Oxidative Decarboxylation ◽  
Pharmaceutical Ingredients ◽  
Synthetic Amino Acids ◽  
Electrochemical Approach ◽  
Synthetic Intermediates ◽  
Space Time Yield ◽  
Aliphatic Carboxylic Acids

Introduction of acetoxy groups to organic molecules is important for the preparation of many active ingredients and synthetic intermediates. A commonly used and attractive strategy is the oxidative decarboxylation of aliphatic carboxylic acids, which entails the generation of a new C(sp3)-O bond. This reaction has been traditionally carried out using excess amounts of harmful lead(IV) acetate. A sustainable alternative to stoichiometric oxidants is the Hofer-Moest reaction, which relies in the 2-electron anodic oxidation of the carboxylic acid. However, examples showing electrochemical acetoxylation of amino acids are scarce. Herein we present a general and scalable procedure for the anodic decarboxylative acetoxylation of amino acids in batch and continuous flow mode. The procedure has been applied to the derivatization of several natural and synthetic amino acids, including key intermediates for the synthesis of active pharmaceutical ingredients. Good to excellent yields were obtained in all cases. Transfer of the process from batch to a continuous flow cell signficantly increased reaction throughput and space-time yield, with excellent product yields obtained even in a single-pass. The sustainability of the electrochemical protocol has been examined by evaluating its green metrics. Comparison with the conventional method demonstrates that an electrochemical approach has a significant positive effect on the greenness of the process

scholarly journals A Semi-Automated Bone Pretreatment System and the Pretreatment of Older and Contaminated Samples

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 247-253 ◽  
Author(s):  
I A Law ◽  
R E M Hedges
Keyword(s):  
Amino Acids ◽  
Cation Exchange ◽  
Continuous Flow ◽  
Exchange Resin ◽  
Flow System ◽  
Cation Exchange Resin ◽  
Flow Cells ◽  
Continuous Flow System ◽  
New Process ◽  
Degree Of Purification

A semi-automated continuous-flow system used to process archaeological bone to purified gelatin or amino acids for 14C dating is described. Powdered bone is retained in flow cells specifically designed to permit the sequential leaching of the bone with acid, alkali and water. Crude collagen obtained by this process is gelatinized, and than either purified directly using a macroporous cation exchange resin (BioRad AGMP-50), or hydrolyzed and the amino acids desalted on BioRad 50W-X8 resin. When compared with previous methods used by the laboratory, the new method allows more samples to be treated to a higher degree of purification. Examples of dates obtained on “standard” bones are presented, and confirm that no contamination is introduced from the components used in the new process.

Efficient continuous-flow benzotriazole activation and coupling of amino acids

2015 ◽  
Vol 5 (4) ◽  
pp. 220-227 ◽  
Author(s):  
Sofie Seghers ◽  
Frederik E.A. Van Waes ◽  
Ana Cukalovic ◽  
Jean-Christophe M. Monbaliu ◽  
Jeroen De Visscher ◽  
...  
Keyword(s):  
Amino Acids ◽  
Continuous Flow

SYNTHESIS OF MACROMOLECULES IN MAIZE ROOT TIPS

1967 ◽  
Vol 45 (4) ◽  
pp. 385-394 ◽  
Author(s):  
Ann Oaks
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Continuous Flow ◽  
Flow System ◽  
Dry Weight ◽  
Maximal Rate ◽  
Root Tips ◽  
Corn Roots ◽  
Rate Of Increase ◽  
Cell Wall Carbohydrates

Corn roots grown in a glucose–salts medium in a continuous flow system suffered an initial loss of protein before an increase was observed. A maximal rate of increase in cell-wall carbohydrates was achieved after 20 hours in culture. There was some loss in RNA while the increase in DNA was slight. A synthetic mixture of 15 L-amino acids enhanced the growth (defined as increase in length, dry weight, or alcohol-insoluble nitrogen) of glucose-grown roots. With this enriched medium there was a slight increase of protein over the initial 20-hour period and a faster rate of increase after this time. No lag in the increase in cell-wall carbohydrates was observed. Despite these symptoms of better growth the level of DNA was not improved by the addition of the amino acids and the RNA content was actually lower than in the glucose-grown roots. Although the level of RNA was less in cultured than in normal roots, ribosomal and soluble RNA accounted for similar proportions of the total RNA in each case.

Continuous flow derivatization system coupled to capillary electrophoresis for the determination of amino acids

2002 ◽  
Vol 976 (1-2) ◽  
pp. 55-64 ◽  
Author(s):  
Rosa M Latorre ◽  
Javier Saurina ◽  
Santiago Hernández-Cassou
Keyword(s):  
Amino Acids ◽  
Capillary Electrophoresis ◽  
Continuous Flow

Continuous-flow protocol for the synthesis of enantiomerically pure intermediates of anti epilepsy and anti tuberculosis active pharmaceutical ingredients

2019 ◽  
Vol 17 (6) ◽  
pp. 1552-1557 ◽  
Author(s):  
Renata M. Aguiar ◽  
Raquel A. C. Leão ◽  
Alejandro Mata ◽  
David Cantillo ◽  
C. Oliver Kappe ◽  
...  
Keyword(s):  
Amino Acids ◽  
Continuous Flow ◽  
Building Blocks ◽  
Active Pharmaceutical Ingredients ◽  
Enantiomerically Pure ◽  
Pharmaceutical Ingredients ◽  
Chiral Intermediates

Continuous-flow production of chiral intermediates plays an important role in the development of building blocks for Active Pharmaceutical Ingredients (APIs), being α-amino acids and their derivatives widely applied as building blocks.

Improved continuous-flow method for detemination of total serum hexosamines.

1976 ◽  
Vol 22 (8) ◽  
pp. 1394-1396 ◽  
Author(s):  
P Z Sobocinski ◽  
W J Canterbury ◽  
K H Jurgens
Keyword(s):  
Amino Acids ◽  
Acid Hydrolysis ◽  
Continuous Flow ◽  
Total Serum ◽  
Manual Method ◽  
Flow Method ◽  
Hydrolysis Of ◽  
Automated Determination ◽  
Continuous Flow Method

Abstract We describe an automated determination of serum hexosamine by the Elson-Morgan reaction, together with reagent modifications that minimiz interference from amino acids and sugars present in acid hydrolysates of sera. We used a novel 15-min autoclave procedure for the acid hydrolysis of sera before analysis to facilitate the detemination as compared to the 4-h hydrolysis used in the conventional manual method. Results correlated well (r = 0.906) with those obtained by the corresponding manual method.

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