Study on the Scale-Up of Phase-Transfer-Catalyzed Azo Coupling Reactions in Flow Reactors

Akwi, Faith M.; Watts, Paul

doi:10.1007/s10593-017-1990-3

Cited by 9 publications

(9 citation statements)

References 17 publications

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“…93 Furthermore, the same group successfully explored surfactants, such as sodium dioctyl sulfosuccinate, as phase transfer catalysts to promote azo coupling reactions in continuous flow systems. 92,94 The addition of a phase transfer catalyst is conducive to the coupling of waterinsoluble coupling agents (e.g., phenol and aniline), which can promote the reduction of the surface tension between the liquid and the liquid phase and stabilize the formation of the liquid-liquid interface. The closer the added amount is to the critical micelle concentration, the more stable the effect of the phase transfer catalyst (Fig.…”

Section: Reaction Chemistry and Engineering Reviewmentioning

confidence: 99%

“…The use of organic solvents as hydrogen donors to achieve reduction in continuous flow was reported by Basso et al in 2019. 157 But their purpose is to obtain the coupling product (92) of acetonyl radicals (93) and olefins (94), which requires that the interaction between aryl radicals and olefins be prevented to shift the reactivity toward HAT (Scheme 41). This is a system in which the Meerwein pathway competes with HAT.…”

Section: Hydro-dediazotizationmentioning

confidence: 99%

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Revisiting aromatic diazotization and aryl diazonium salts in continuous flow: highlighted research during 2001–2021

et al. 2022

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Section: Reaction Chemistry and Engineering Reviewmentioning

confidence: 99%

Section: Hydro-dediazotizationmentioning

confidence: 99%

Revisiting aromatic diazotization and aryl diazonium salts in continuous flow: highlighted research during 2001–2021

et al. 2022

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“…The continuous-flow synthesis of azo dyes in a microreactor system was also studied. The synthesis of the azo dye was the same as that of azo pigments, and as reported in the literature, excellent results, such as a high product yield and selectivity and a short reaction time were obtained by using microreactor technology. − However, to date, there are few reports about the continuous-flow synthesis of C.I. PR 146 in a microreactor system.…”

Section: Introductionmentioning

confidence: 99%

Continuous-Flow Synthesis of Pigment Red 146 in a Microreactor System

Wang

Ding

2019

Ind. Eng. Chem. Res.

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In this study, a continuous-flow coupling reaction method has been developed for the synthesis of Pigment Red 146 (C.I. PR 146). A computational fluid dynamics simulation was used to evaluate the effects of the micromixer structures on the mixing process. After the optimization of the microreactor structures and the reaction conditions, the conversion of the coupling reaction reached more than 99% using a microsieve pore dispersion reactor (two microsieve pores arranged side by side) and a smaller particle size and narrower particle-size distribution were obtained than were obtained in conventional batch reactors. Furthermore, the lightness and the green and the blue hues of these pigment products were more intense than those of the C.I. PR 146 standard. The largest conformity of the hue of the pigment products compared with the C.I. PR 146 standard was obtained using a microsieve pore dispersion reactor under the optimized reaction conditions. Finally, a scaling-up study of the pigment synthesis process in the microreactor system was initially explored. In conclusion, the microreactor system led to an improvement of the pigment products, and this method has a good industrial value.

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“…Lin et al [12] found that an increase in pipe diameter pushed the transition from stratified to slug flow towards higher liquid velocities for air-water flow. However, even for stable Taylor flow, an increase in the reactor diameter has often resulted in reduced conversion and/or yield [13,14] and mass transfer [15,16] due to the subsequent reduction in specific surface area and thus interfacial transport. Another important aspect that needs to be thoroughly examined during scale-up by increasing the characteristic length scale is reactor safety.…”

Section: Introductionmentioning

confidence: 99%