A Continuous-Flow Microwave Reactor for Conducting High-Temperature and High-Pressure Chemical Reactions

Abstract

A continuous-flow microwave reactor with a unique pressure control device is described. The reactor has been designed to withstand extremely high pressure without the involvement of a conventional backpressure-creating device that commonly results in carryover and cross-contamination problems. The reactor efficiency has been evaluated by product conversions using two model reactions, namely, the Claisen rearrangement and the synthesis of benzimidazole.

Continuous‐Flow Microwave Synthesis of Metal–Organic Frameworks: A Highly Efficient Method for Large‐Scale Production

“…is introduced into the heating cavity of a CEM MARS 5 multimode MW synthesizer. Downstream of the oven, the tube is introduced into a custom‐made pressurized collecting unit made of glass, similar to those recently described by Sauks and co‐workers and by Deadman and co‐workers . The pumps and the MW oven are remotely controlled from a laptop computer.…”

“…TheP TFE tubular reactor (4.35 mm I.D.) is introduced into the heating cavity of aC EM MARS 5m ultimode MW synthesizer.D ownstream of the oven, the tube is introduced into ac ustom-made pressurized collecting unit made of glass, similar to those recently described by Sauks and co-workers [33] andb yD eadman and coworkers. [34] The pumpsa nd the MW oven are remotelyc ontrolled from al aptop computer.T he present system is as ocalled plug-flowr eactor,i nc ontrast with the continuously stirred tank reactor recently developed andp atented by Jhung and co-workers.…”

Machine‐Assisted Organic Synthesis

“…[48] This is especially the case in microwave-heated vessels,w here supplied energy is absorbed directly by the reactants and solvents,p otentially leading to localized superheating and rapid exotherms.O rgan'sr esearch group has developed abackpressure regulator system that enables their previously reported continuous-flow microwave system to be used at pressures exceeding 73 bar (the boiling point for water at this pressure is 288 8 8C). [49] Agas is used to maintain the pressure, rather than am echanical part, and so this system is ideal for use in situations where precipitation occurs or where traditional backpressure regulators are exposed to damaging agents.O ur group has recently reported as imilar device that can be used for the backpressure regulation of fluid streams that contain solids. [50] One of the most original examples of the use of microwaves in organic synthesis was reported in 2006 whereby af lowing-through capillary equipped with am icrowave reactor was developed ( Figure 10).…”

Advances in steady-state continuous-flow purification by small-scale free-flow electrophoresis

“…Fine chemical synthesis strategies changed over the past decade when small-scale continuous-flow synthesis was developed using capillary and channel micro-reactors. The advantages of small-scale continuous-flow synthesis, over a batch approach, include: (1) greater control over the precision of reaction conditions (i.e., temperature, pressure, quality of mixing) [5,6]; (2) ii) ability to use high temperature and pressure [7];…”