Going with the flow

Laboratory chemists are looking to industry for methods to carry out large scale syntheses using multi-channel microreactors.

A team of researchers, led by Graham Sandford at the University of Durham, UK, in collaboration with the Asahi Glass Company, Japan, has developed microreactor devices that can be used long term in both laboratory and industrial applications.

Away from industry, flow systems are seldom used, however the case for using microreactors in a laboratory situation is growing. This group’s pioneering work shows how a single channel device can be multiplied to carry out a reaction on a significantly larger scale.

They have found that up to 30 channels operating in parallel can be run simultaneously, meaning that very large quantities of product can be obtained in a single batch. A single reservoir supplies each channel with a steady flow of reactants under constant conditions.

The researchers at Durham have applied this microreactor apparatus to fluorination reactions, particularly beta-ketoesters. Introducing fluorine regioselectively into organic systems can be a challenge. Ideally, elemental fluorine reacts with the organic species but using conventional laboratory techniques for this can be a hazardous task. The reactor contains the process in a closed system, thus reducing the risks.

This procedure uses only cheap and readily available techniques and equipment which makes it viable and convenient for many applications. ’In theory, all speciality chemicals could be synthesised very quickly and continuously using these very versatile multi-channel reactor operating systems,’ says Sandford.

Sophia Anderton