Flow Chemistry

What is Flow Chemistry?

Flow chemistry, sometimes referred to as plug flow, microchemistry or continuous flow chemistry is the process of performing chemical reactions in a tube or pipe. Reactive components are pumped together at a mixing junction and flowed down a temperature controlled pipe or tube.

The major advantages of flow chemistry are faster reactions, cleaner products, safer reactions, quick reaction optimization, easy scale-up, and the integration of typically separate processes (such as synthesis, work-up, and analysis).

Syrris is the world’s longest established provider of lab scale flow chemistry systems. These systems are called Asia and Titan and allow easy access to the benefits of flow chemistry.

The Benefits of Flow Chemistry

Faster Reactions

Flow reactors are easily pressurized (e.g. Asia systems can be pressurized to 300psi). This allows reactions to be heated 100-150ºC above their normal boiling point, therefore, creating reaction rates that are 1000s of times faster. This process is called superheating.

Cleaner Products

Flow reactors enable excellent reaction selectivity. The rapid diffusion mixing avoids the issues found in batch reactors. The high surface area to volume ratio (1000x greater than a batch reactor) enables almost instantaneous heating or cooling and therefore ultimate temperature control.

Safer Reactions

Flow chemistry allows only a small amount of hazardous intermediate to be formed at any instant. The high surface area also allows excellent control of exotherms.

Integrated Synthesis, Work-up and Analysis

Reaction products exiting a flow reactor can be flowed into a flow aqueous work-up system or solid phase scavenger column. From there they can be analyzed either in line (e.g. FTIR) or a sample taken, using a sampler and diluter then and injected onto and LCMS.

Rapid Reaction Optimization

Flow Chemistry with automation enables the quick variation of reaction conditions on a very small scale e.g. 100µl. Parameters such as reaction time, temperature, ratio of reagents, concentration and reagents themselves can all be rapidly varied. One reaction can follow another, separated by solvent, each cleaning out the previous reaction.

Easy Scale-Up

Scale up issues are minimized due to maintaining excellent mixing and heat transfer. Higher flow rates and correspondingly larger reactors can be used to easily produce kilogram quantities.

Reaction Conditions Not Possible in Batch

Flow chemistry facilitates reaction conditions not possible in batch such as a 5-second reaction at 250ºC. Multi step procedures such as a rapid low-temperature deprotonation followed instantaneously by the addition of an electrophile high temperature are made easy.

This section provides information about the application of flow chemistry. Please use the navigation to the left to access more specialist flow chemistry information.

For information on Syrris flow chemistry products, click on Asia.

Syrris Glass Microreactor in Holder
Diffusional Mixing in Microreactors
Syrris glass Microreactor in Holder

Examples of Flow Chemistry

Oxidation of a Primary Alcohol

Syrris has a range of resources that demonstrate a variety of flow chemistry application notes and reactions using Syrris’ flow chemistry systems. Syrris’ innovative microreactor based systems include the modular Asia and Africa product ranges. Here are two examples shown below:

Oxidation of primary alcohols using solid supported N-alkylammonium perruthenate
This paper describes reaction conditions for the oxidation of alcohols in continuous flow using a column reactor packed with polymer-supported tetra-N-alkylammonium perruthenate.

Organic Synthesis

Steven V. Ley, Ian R. Baxendale, Jon Deeley, Charlotte M. Griffiths-Jones, Steen Saaby, Geoffrey K. Tranmer (University of Cambridge)

Syrris Asia

Williamson Ether Synthesis

This paper describes a multi-step formation of functionalized indoles. This step focuses on a high yielding Williamson ether synthesis using Methanol as a nucleophile.
This paper describes a multi-step formation of functionalized indoles. This step focuses on a high yielding Williamson ether synthesis using Methanol as a nucleophile.

Organic Synthesis

Thomas Tricotet and Donal O’Shea (University College Dublin)

Syrris Asia

A photograph of the Syrris Asia Flow Chemistry system
Syrris Asia Flow Chemistry System
Syrris Asia Advanced System