scholarly journals Diels–Alder reactions of myrcene using intensified continuous-flow reactors

2017 ◽  
Vol 13 ◽  
pp. 120-126 ◽  
Author(s):  
Christian H Hornung ◽  
Miguel Á Álvarez-Diéguez ◽  
Thomas M Kohl ◽  
John Tsanaktsidis

This work describes the Diels–Alder reaction of the naturally occurring substituted butadiene, myrcene, with a range of different naturally occurring and synthetic dienophiles. The synthesis of the Diels–Alder adduct from myrcene and acrylic acid, containing surfactant properties, was scaled-up in a plate-type continuous-flow reactor with a volume of 105 mL to a throughput of 2.79 kg of the final product per day. This continuous-flow approach provides a facile alternative scale-up route to conventional batch processing, and it helps to intensify the synthesis protocol by applying higher reaction temperatures and shorter reaction times.

2018 ◽  
Vol 14 ◽  
pp. 318-324 ◽  
Author(s):  
Imane Nekkaa ◽  
Márta Palkó ◽  
István M Mándity ◽  
Ferenc Fülöp

The syntheses of various pyrimidinones as potentially bioactive products by means of the highly controlled continuous-flow retro-Diels–Alder reaction of condensed pyrimidinone derivatives are presented. Noteworthy, the use of this approach allowed us to rapidly screen a selection of conditions and quickly confirm the viability of preparing the desired pyrimidinones in short reaction times. Yields typically higher than those published earlier using conventional batch or microwave processes were achieved.


Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1002 ◽  
Author(s):  
Maïté Audemar ◽  
Yantao Wang ◽  
Deyang Zhao ◽  
Sébastien Royer ◽  
François Jérôme ◽  
...  

Furfural is a platform molecule obtained from hemicellulose. Among the products that can be produced from furfural, furfuryl alcohol is one of the most extensively studied. It is synthesized at an industrial scale in the presence of CuCr catalyst, but this process suffers from an environmental negative impact. Here, we demonstrate that a non-noble metal catalyst (Co/SiO2) was active (100% conversion of furfural) and selective (100% selectivity to furfuryl alcohol) in the hydrogenation of furfural to furfuryl alcohol at 150 °C under 20 bar of hydrogen. This catalyst was recyclable up to 3 cycles, and then the activity decreased. Thus, a comparison between batch and continuous flow reactors shows that changing the reactor type helps to increase the stability of the catalyst and the space-time yield. This study shows that using a continuous flow reactor can be a solution to the catalyst suffering from a lack of stability in the batch process.


1991 ◽  
Vol 23 (4-6) ◽  
pp. 1001-1010 ◽  
Author(s):  
M. Okada ◽  
T. Nakamura ◽  
H. Ito ◽  
A. Murakami

The process to gain and lose phenol degrading activity of activated sludge under different stress of phenol was studied by three types of operations, i.e. continuous flow reactor, aerobic SBR, and anaerobic/aerobic SBR under two types of loads, i.e. elevating and constant loads. The higher activity and tolerance under the higher concentration of phenol was gained in activated sludge of aerobic SBR under the constant high load. The higher phenolic stress, i.e. mixed liquor concentration of phenol, at the beginning of batch cycles seemed to increase the activity. Constant and low phenolic stress in continuous flow reactors and elevating load in SBR, however, could not build up tolerance and the higher degrading activity under the higher concentration of phenol. SBR operations which are able to give appropriate phenolic stress on activated sludge, even under the same daily loading of phenol as continuous flow reactor, would be preferable to build up and maintain the activity and to ensure stable operation of wastewater treatment even under shock loading. The degrading activity of activated sludge may be gained mainly by the increase in the ability of bacteria to degrade and tolerate phenol and not by the increase in population.


2019 ◽  
Vol 4 (2) ◽  
pp. 362-367 ◽  
Author(s):  
Renan Galaverna ◽  
Lucas P. Fernandes ◽  
Duncan L. Browne ◽  
Julio C. Pastre

A Diels–Alder reaction employing terpenes for rapid synthesis of monomer libraries under flow conditions is presented.


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