Vapourtec’s R-Series High-Pressure pump module is used for running continuous flow reactions under solvent free (neat) conditions and pumping liquefied gases at pressures necessary for high reaction temperatures. These higher temperature and pressure conditions enable solvent-free uncatalysed amination of 2-chloropyridine with dimethylamine in high throughput (30g/hr), the company says.
The new pump module allows the R-Series systems to reach up to 200 bar, while also having the functionality of Vapourtec’s standard pump modules (including full integration with the FlowCommander software). It can also be added to an existing two-pump system for increased capability.
In continuous flow chemistry the reaction temperature is limited by the boiling point of the solvents and reagents. Increased pressure leads to increased boiling point, opening up opportunities for new reaction methodologies. For example operating at high temperatures may eliminate the need for a catalyst, reducing cost, environmental impact and simplifying reaction work up. At 250°C the vapour pressure of ethanol, methanol and dimethylamine are 66 bar, 88 bar and 150 bar respectively.
Vapourtec says flow reactors can be safely run at such high pressures. Unlike traditional batch or microwave reactors, they contain no compressible gaseous headspace, and a very small reaction inventory compared with the batch size. Maintaining all reagents in the liquid phase ensures precise control over reaction stoichiometry even when using volatile reagents such as dimethylamine.
In addition to raising the reaction temperature above a solvent’s boiling point, the Vapourtec High Pressure Pump Module’s capability is of advantage in applications where reactor backpressures may be significant, such as in ionic liquid synthesis, polymer synthesis or in reactions using microbore reactors to achieve a combination of rapid mixing and excellent heat transfer. The company describes the system in an Application Note on its website.
