Acylation of m-cresol with acetic acid supported by in-situ ester formation on H-ZSM-5 zeolites

2021 ◽  
Author(s):  
Han K. Chau ◽  
Daniel E. Resasco ◽  
Phuong Do ◽  
Steven P. Crossley
Keyword(s):  
Acetic Acid ◽  
Ester Formation

Acetic acid mediated regioselective synthesis of 2,4,5-trisubstituted thiazoles by a domino multicomponent reaction

2019 ◽  
Vol 43 (22) ◽  
pp. 8644-8650 ◽  
Author(s):  
Mohit Saroha ◽  
Jitender M. Khurana
Keyword(s):  
Acetic Acid ◽  
Multicomponent Reaction ◽  
Regioselective Synthesis ◽  
Domino Reaction ◽  
Thiazole Derivatives ◽  
Active Methylene

Acetic acid mediated regioselective synthesis of novel 2,4,5-trisubstituted thiazole derivatives has been reported by a domino reaction of thiosemicarbazide and aldehydes/ketones/isatin, to generate thiosemicarbazones (in situ) followed by addition of arylglyoxal and active methylene/activated C–H acids/pyrazole/indole in ethanol at 80 °C.

Development of novel sourdoughs with in situ formed exopolysaccharides from acetic acid bacteria

2015 ◽  
Vol 241 (2) ◽  
pp. 185-197 ◽  
Author(s):  
Maria Hermann ◽  
Hannes Petermeier ◽  
Rudi F. Vogel
Keyword(s):  
Acetic Acid ◽  
Acetic Acid Bacteria

Instabilities in the System NMMO/Water/Cellulose (Lyocell Process) Caused by Polonowski Type Reactions

Holzforschung ◽  
2002 ◽  
Vol 56 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Thomas Rosenau ◽  
Antje Potthast ◽  
Andreas Hofinger ◽  
Herbert Sixta ◽  
Paul Kosma
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Exchange Resin ◽  
Degradation Products ◽  
Ion Exchange Resin ◽  
Low Molecular Weight ◽  
Acid Component ◽  
Degradation Reactions ◽  
Polyglucuronic Acid

Summary Polonowski type degradation reactions are a major reason for the frequently observed instability of solutions of cellulose in N-methylmorpholine-N-oxide monohydrate (NMMO, 1). The degradation is induced by degradation products of cellulose and NMMO generated in situ in the Lyocell system. The presence of both an amine component, such as morpholine or N-methylmorpholine, and an acid component is required for the decomposition process to proceed. The latter might be a low-molecular-weight compound, such as formic acid, acetic acid or gluconic acid, or also a high-molecular-weight acid, such as polyglucuronic acid or ion exchange resin.

A new emulsification-crosslinking technique for preparation of physically crosslinked chitosan microspheres

2020 ◽  
Vol 35 (4-5) ◽  
pp. 289-300
Author(s):  
Aiping Shi ◽  
Ying Guan ◽  
Yongjun Zhang
Keyword(s):  
Acetic Acid ◽  
Chitosan Solution ◽  
Curing Temperature ◽  
Urea Solution ◽  
Chitosan Microspheres ◽  
Model Protein ◽  
Crosslinked Chitosan ◽  
Physically Crosslinked ◽  
Emulsifier Concentration

A new emulsification-crosslinking method was developed for the preparation of chitosan microspheres. The new method uses an aqueous alkali–urea solution, instead of the commonly used acidic solvents, to dissolve chitosan. After emulsification, the water-in-oil droplets are solidified by heating, taking advantage of the unique in situ thermal gelling behavior of the alkaline chitosan solution, instead of by crosslinking with a usually toxic crosslinker. The size of the microspheres can be controlled by the concentration of chitosan solution, stirring speed, emulsifier concentration, and the curing temperature. The resulting microspheres are physically crosslinked, instead of chemically crosslinked, and they are ready to dissolve in dilute acetic acid. The resulting chitosan microspheres are non-toxic and can be degraded by lysozyme. Bovine serum albumin, a model protein, can be facilely loaded into the microspheres by adsorption, and then released from the microspheres.

scholarly journals The first in situ synthesis of 1,3-dioxan-5-one derivatives and their direct use in Claisen-Schmidt reactions

2019 ◽  
Vol 25 (1) ◽  
pp. 85-90 ◽  
Author(s):  
M. Javad Poursharifi ◽  
Mohammad M. Mojtahedi ◽  
M. Saeed Abaee ◽  
Mohammad M. Hashemi
Keyword(s):  
Acetic Acid ◽  
Aromatic Aldehydes ◽  
In Situ Synthesis ◽  
Stepwise Procedures ◽  
Time Periods ◽  
High Yields ◽  
Short Time ◽  
Direct Use ◽  
Derivatives Of

AbstractA method is developed for in situ generation of 1,3-dioxan-5-one derivatives 2. These compounds are simple precursors for accessing carbohydrate structures and previously had to be produced via stepwise procedures using excessive amounts of reagents. In the present work, three different derivatives of 2 were synthesized via the reaction of trialkoxyalkanes with dihydroxyacetone dimer 1 in the presence of acetic acid as the catalyst. In the same pot, derivatives of 2 were reacted with aromatic aldehydes and 30 mol% of pyrrolidine to obtain high yields of the respective bischalcones 3 within short time periods.

scholarly journals From a Basic Microalga and an Acetic Acid Bacterium Cellulose Producer to a Living Symbiotic Biofilm

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2275
Author(s):  
Vítor Nóbrega ◽  
Marisa Faria ◽  
Antera Quintana ◽  
Manfred Kaufmann ◽  
Artur Ferreira ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Acetic Acid Bacterium ◽  
Growth Media ◽  
Media Composition ◽  
Symbiotic Interaction ◽  
Microalgae Biomass ◽  
The Subject ◽  
Living Material ◽  
First Time

Bacterial cellulose (BC) has recently been the subject of a considerable amount of research, not only for its environmentally friendly biosynthesis, but also for its high potential in areas such as biomedicine or biomaterials. A symbiotic relationship between a photosynthetic microalga, Chlamydomonas debaryana, and a cellulose producer bacterium, Komagataeibacter saccharivorans, was established in order to obtain a viable and active biofilm. The effect of the growth media composition ratio on the produced living material was investigated, as well as the microalgae biomass quantity, temperature, and incubation time. The optimal temperature for higher symbiotic biofilm production was 30 °C with an incubation period of 14 days. The high microalgae presence, 0.75% w/v, and 60:40 HS:BG-11 medium (v/v) induced a biofilm microalgae incorporation rate of 85%. The obtained results report, for the first time, a successful symbiotic interaction developed in situ between an alkaline photosynthetic microalga and an acetic acid bacterium. These results are promising and open a new window to BC living biofilm applications in medical fields that have not yet been explored.

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