29 research outputs found
Photochemical synthesis of a âcageâ compound in a microreactor: Rigorous comparison with a batch photoreactor
An intramolecular [2 + 2] photocycloaddition is performed in a microphotoreactor (0.81 mL) built by winding FEP tubing around a commercially available Pyrex immersion well in which a medium pressure mercury lamp is inserted. A rigorous comparison with a batch photoreactor (225 mL) is proposed by means of a simple model coupling the reaction kinetics with the mass, momentum and radiative transfer
equations. This serves as a basis to explain why the chemical conversion and the irradiation time are respectively increased and reduced in the microphotoreactor relative to those in the batch photoreactor. Through this simple model reaction, some criteria for transposing photochemical synthesis from a batch photoreactor to a continuous microphotoreactor are defined
La micro-échelle en synthÚse organique : un outil commun chimie/génie chimique
Cet article est une restitution courte de la prĂ©sentation rĂ©alisĂ©e au cours des JIREC 2013 sur lâenseignement de la notion de changement dâĂ©chelle et de passage dâun mode batch Ă un mode continu en synthĂšse organique. Lâenjeu est de faire travailler des Ă©tudiants issus des dĂ©partements chimie et gĂ©nie chimique autour dâun mĂȘme outil, le microrĂ©acteur. Au cours dâune sĂ©ance de travaux pratiques, les Ă©tudiants mettent en oeuvre une synthĂšse organique en continu Ă micro-Ă©chelle et comparent les rĂ©sultats obtenus Ă ceux du procĂ©dĂ© batch. Ils apprĂ©hendent ainsi la notion de synthĂšse en continu et de suivi cinĂ©tique le long du microrĂ©acteur et comprennent lâintĂ©rĂȘt et les difficultĂ©s liĂ©s Ă la petite Ă©chelle. Lâoutil microrĂ©acteur mis en place Ă lâINP-ENSIACET peut ĂȘtre transfĂ©rĂ© vers dâautres formations de type ingĂ©nieurs, mais aussi CPGE, BTS ou IUT, pour accompagner le lien entre les domaines « gĂ©nie de la rĂ©action » et « synthĂšse organique »
Gold(I) complexes bearing phosphole ligands: Synthesis and antimalarial activity
AbstractA series of gold(I)-monophosphole complexes have been synthesized and characterized. The introduction of a nitrogen moiety in the complex structure was envisioned either by choosing the bis(trifluoromethanesulfonyl)imidate ligand as the X-ligand or by preparing a new pyrrolidinophosphole ligand as the L-ligand. All the complexes have been evaluated in vitro for their antimalarial activity. These goldâphosphole complexes showed moderate activities with IC50 values ranging from 9.7 to 24 ΌM against Plasmodium falciparum chloroquine-resistant strains
Retour d'expérience sur un dispositif de Réflexivité et de Contextualisation en formation d'ingénieur par Apprentissage : RéCAp
International audienceRĂ©CAp est un dispositif de problĂ©matisation permettant de mettre en lien les expĂ©riences professionnelles vĂ©cues en entreprise et les savoirs acadĂ©miques dispensĂ©s dans les formations par apprentissage de Toulouse INP-ENSIACET. Lâobjectif de ce dispositif est double : (i) pour les Ă©lĂšves, il sâagit de les initier Ă une analyse rĂ©flexive de leurs activitĂ©s et de leur positionnement en entreprise et de les accompagner dans la co-construction de leurs apprentissages Ă partir de la mise en relation des expĂ©riences en entreprise et des enseignements Ă lâĂ©cole, (ii) pour les enseignants, il sâagit de leur donner lâopportunitĂ© de mieux contextualiser leurs enseignements et de mieux apprĂ©hender la notion de compĂ©tences au travers de situations authentique complexes. Par ailleurs, ce dispositif est suffisamment souple pour ĂȘtre adaptĂ© Ă diffĂ©rents contextes et il permet de relever le dĂ©fi de la coopĂ©ration via sa dimension collaborative tant au niveau des Ă©lĂšves que des enseignants
Microreactors as a Tool for Acquiring Kinetic Data on Photochemical Reactions
For the first time, the application of microreactors as a tool for acquiring kinetic data on a photochemical reaction is demonstrated. For illustration, a T-photochromic system is considered. By using modeling tools and carrying out specific experiments in a spiral-shaped microreactor irradiated by an ultraviolet/light-emitting diode (UV-LED) array, the two kinetic parameters of the reaction, namely, quantum yield and rate of thermal back reaction, are determined. Once these parameters are known, the photochromic reaction is performed in two other microreactors in order to investigate a wider range of operating conditions. It is observed that a critical residence time exists beyond which the conversion into the open form decreases due to a decomposition reaction. The value of the critical residence depends on the microreactor type, which can be predicted by applying the model developed
Photooxygenation in an advanced led-driven flow reactor module: experimental investigations and modelling
The photooxygenation of âŻÎ±-terpinene was investigated as a benchmark reaction in an advanced LED-driven flow reactor module, both from an experimental and modelling point of view. Ethanol was used as a green solvent and rose Bengal was chosen as a cheap sensitizer of industrial importance. Firstly, the kinetic law based on all mechanistic steps was established for the chosen photooxygenation. From this, the set of operating parameters potentially influencing the photoreaction rate were identified. Subsequently, experiments were carried out under continuous-flow conditions to screen these operating parameters, namely concentration of α-terpinene, concentration of photosensitizer, residence time, structure of the segmented gas-liquid flow and nature of the reagent gas phase (air versus pure oxygen). Finally, the conditions enabling minimization of sensitizer bleaching were established. It was also shown that the hydrodynamic characteristics of the gas-liquid flow can have an effect on the conversion levels. From this, a simplified model was proposed to predict the conversion at the reactorâs outlet when pure oxygen was used
Synthesis and biological evaluation of a new trioxaquine containing a trioxane moiety obtained by halogenocyclisation of a hemiperoxyacetal
Transposition of a triphosgene-based process for pharmaceutical development: from mg·h-1 to kg·h-1 of an unsymmetrical urea
A two reaction synthesis of a urea, using triphosgene, was studied. The objective was to transpose the process from laboratory scale to pre-industrial plant. The whole study was performed in a continuous process, adapting the characteristic dimensions and length of the reactor. In this paper, the development of the process is presented, and the choices about safety and operating conditions constraints are discussed. The final operation allows a 70% global yield in a 7 week study. Furthermore, the use of microreactors not only permits an exhaustive study of the process operating parameters, but also provides feedback on the developed chemistry itself. The results obtained are a demonstration of the use of continuous processes in small scale reactors for complex molecule development. The mg·h-1 to kg·h-1 is a key transposition in the pharmaceutical industries project development, as it can help to accelerate the first lot production used in toxicological or pre-clinic stages
A revised experimental protocol for implementing the actinometry method with the Reineckeâs salt
The present short note aims at proposing a revised experimental protocol to implement the actinometry method with Reineckeâs salt. It consists in substituting - for the dosing of the thiocyanate anions produced - perchloric acid (HClO4) by nitric acid (HNO3) - the latter being carefully chosen regarding the chemical equilibria occurring in the aqueous medium and the moderate risks of HNO3. This substitution has been rigorously validated by carrying out the experiments in a dedicated torus batch photoreactor enabling simple treatment of experimental results from a one-dimensional model
Flow photochemistry: a meso-scale reactor for industrial applications
Developing flow photochemistry, especially at meso-scale where significant productivity is required, remains challenging. There is a need for innovative equipments generating highly controlled flow under light irradiation. In this work, a commercial solution, developed by Corning, is presented and studied by LGC and MEPI on an intramolecular (2+2) photo-cycloaddition. Detailed experimental and modelling analysis has been performed to emphasize the flow reactor behaviour and performances, and demonstrate its capability in producing up to 30g.h-1 of the desired molecule. Through this simple model reaction, the G1 photo-reactor is shown to be an efficient meso-scale reactor for industrial photo-applications development and production