FLOW CHEMISTRY
The UV-150 is Vapourtec ’ s photochemical reactor The VFBR can carry out SPS in flow
Solid-phase synthesis
‣ One of the rapidly expanding areas of continuous flow has been solidphase synthesis , where a solid media substrate is used to build molecules step by step . Peptides , oligonucleotides and oligosaccharides have all been synthesised in continuous flow , yielding a more efficient synthesis thanks to the interaction between the solid media and the reagents . 15-18 Peptide synthesis in flow has been explored in the past but has been limited to the use of packed bed reactors . However , these have a fixed volume , do not allow the molecule to grow and can lead to impurities due to the channelling of reagents and / or increased pressure . To address these challenges , Vapourtec launched its Variable Bed Flow Reactor ( VBFR ) in 2020 . This monitors and controls the
packing density of the solid media by changing its internal volume . Thus , there is no channelling of reagents or any pressure build-up throughout the synthesis .
AI in flow
Implementing machine learning into flow chemistry has been the latest big development . Combining an automated flow chemistry platform and self-learning algorithms can potentially reshape the way we understand chemistry . In a nutshell , a self-optimised algorithm plans reactions , modifying the parameters until it reaches its objective . The user then gives a range of reaction parameters for modification - typically residence time , temperature , UV intensity , concentration or even type of solvent – and a set of goals . These cover a broad spectrum ; the optimisation can be focused , for
example , to achieve , lowest cost , highest yield , a more efficient usage of reagents or fastest reaction . Once the goals and parameters have been set and there is a suitable analytical technique to analyse the products , it will start iterating between reaction conditions to meet the goal . By relying on inline analytical techniques , the selfoptimised algorithm will evaluate the success of each run and plan the next reaction ahead . 19 •
Duncan Guthrie
MANAGING DIRECTOR
VAPOURTEC LTD . k + 44 1284 728659 J info @ vapourtec . com j www . vapourtec . com
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14 : Vapourtec , Application Note 61 : Photochemical bromination with elemental bromine in continuous flow , 2018
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56 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981