01761nas a2200253 4500008004100000022001400041245006500055210006400120260007900184300001200263490000600275520092900281653001701210653003001227653001701257653001401274653001401288100001901302700002001321700002201341700002201363700002301385856009901408 2014 eng d a2191-954200aDiscontinuous two step flow synthesis of m-aminoacetophenone0 aDiscontinuous two step flow synthesis of maminoacetophenone aGENTHINER STRASSE 13, D-10785 BERLIN, GERMANYbWALTER DE GRUYTER GMBHcAUG a279-2850 v33 a

The continuous flow nitration of acetophenone followed by reduction of the meta isomer has been demonstrated using simple tubular reactors. Because of ease of separation of the desired isomer from the first step, both steps are made continuous, but separately. The continuous flow nitration was carried out in a safe manner in a shorter reaction time than the conventional approach. The choice of micromixer was seen to affect the performance of the nitration reaction. The effect of different parameters on the yield of the desired product was studied. The reduction step with sodium sulfide was found to be economical and could be carried out efficiently at 70 degrees C using sodium sulfide in ethanol, using a silicone tube. Both steps were demonstrated for several hours, yielding a sufficiently large quantity (similar to 100 g) of m-aminoacetophenone at lab scale in a single day using simple tubular reactors.

10aacetophenone10acontinuous flow synthesis10amicroreactor10anitration10areduction1 aTibhe, Jagdish1 aSharma, Yachita1 aJoshi, Ramesh, A.1 aJoshi, Rohini, R.1 aKulkarni, Amol, A. uhttps://library.ncl.res.in/content/discontinuous-two-step-flow-synthesis-m-aminoacetophenone-002104nas a2200241 4500008004100000022001400041245010000055210006900155260000800224300001400232490000700246520127000253653001501523653003001538653001601568653002901584653002201613100002701635700002701662700002401689700002301713856012601736 2018 eng d a1860-539700aAssessing the possibilities of designing a unified multistep continuous flow synthesis platform0 aAssessing the possibilities of designing a unified multistep con cJUL a1917-19360 v143 a

The multistep flow synthesis of complex molecules has gained momentum over the last few years. A wide range of reaction types and conditions have been integrated seamlessly on a single platform including in-line separation as well as monitoring. Beyond merely getting considered as `flow version' of conventional `one-pot synthesis', multistep flow synthesis has become the next generation tool for creating libraries of new molecules. Here we give a more `engineering' look at the possibility of developing a `unified multistep flow synthesis platform'. A detailed analysis of various scenarios is presented considering 4 different classes of drugs already reported in the literature. The possible complexities that an automated and controlled platform needs to handle are also discussed in detail. Three different design approaches are proposed: (i) one molecule at a time, (ii) many molecules at a time and (iii) cybernetic approach. Each approach would lead to the effortless integration of different synthesis stages and also at different synthesis scales. While one may expect such a platform to operate like a `driverless car' or a `robo chemist' or a `transformer', in reality, such an envisaged system would be much more complex than these examples.

10aautomation10acontinuous flow synthesis10acybernetics10amultistep flow synthesis10aunified platforms1 aSharma, Mrityunjay, K.1 aAcharya, Roopashri, B.1 aShukla, Chinmay, A.1 aKulkarni, Amol, A. uhttps://library.ncl.res.in/content/assessing-possibilities-designing-unified-multistep-continuous-flow-synthesis-platform02149nas a2200241 4500008004100000022001400041245009500055210006900150260000800219300001100227490000800238520134100246653003001587653002301617653001801640653001901658653002201677100001901699700001901718700002601737700002301763856012101786 2023 eng d a1385-894700aTransient response to perturbations in flow synthesis of citrate capped gold nanoparticles0 aTransient response to perturbations in flow synthesis of citrate cAUG a1438900 v4703 a

This work reports the transient behavior of continuous flow synthesis of gold nanoparticles (Au NPs) when subjected to perturbations in operating conditions using controlled experiments. The intricacies are captured through a detailed mathematical model. Reversed Turkevich protocol was used for synthesis of Au NPs. The synthesis was first studied in batch mode to investigate the reaction kinetics and reproducibility of the process. The optimal set of operating conditions viz., residence time, flow rate, temperature was then used for flow synthesis in a 2 m, 1/16 & DPRIME;Polytetrafluoroethylene (PTFE) reactor with micromixer. Reactor clogging was avoided by using segmented flow. Inline UV measurement was used for real time monitoring of the process. Transient experiments were performed by abruptly changing the operating conditions. A mathematical model was found to be accurate in predicting the transient behavior of the exit precursor concentration and the particle size for unsteady state synthesis. Even a small change in process variables for short duration was found to disturb the quality of Au NPs for a significantly longer duration. Of the three operating parameters, the effect of temperature variation was seen to have a prolonged effect where the system remained in unsteady state for long time.

10acontinuous flow synthesis10agold nanoparticles10aParticle size10asegmented flow10aUnsteady behavior1 aBari, Atul, H.1 aShukla, Neerja1 aGavriilidis, Asterios1 aKulkarni, Amol, A. uhttps://library.ncl.res.in/content/transient-response-perturbations-flow-synthesis-citrate-capped-gold-nanoparticles