Continuous flow iodination using an automated computer-vision controlled liquid-liquid extraction system

An Automated Computer-Vision "Bubble-Counting" Technique to Characterise CO2 Dissolution into an Acetonitrile Flow Stream in a Teflon AF-2400 Tube-in-Tube Flow Device

A Teflon AF-2400 based tube-in-tube device was used to generate flow streams of CO₂ in acetonitrile and a computer-vision based 'bubble counting' technique was used to estimate the amount of CO₂ that had passed into solution whilst in the tube-in-tube device by quantifying the amount of CO₂ that left solution (forming separate gas-phase segments) downstream of the back-pressure regulator. For both CO₂ pressures used, there appeared to be a minimum residence time below which no CO₂ was observed to leave solution. This was assumed to be due to residual CO₂ below (or close to) the saturation concentration at atmospheric pressure and, by taking this into account, we were able to fit curves corresponding to simple gradient-driven diffusion and which closely matched previously obtained colorimetric titration data for the same system. The estimated value for the residual concentration of CO₂ (0.37 M) is higher than, but in reasonable general correspondence with, saturation concentrations previously reported for CO₂ in acetonitrile (0.27 M).

Inline purification in continuous flow synthesis – opportunities and challenges

Continuous flow technology has become the method of choice for many academic and industrial researchers when developing new routes to chemical compounds of interest. With this technology maturing over the last decades, robust and oftentimes automated processes are now commonly exploited to generate fine chemical building blocks. The integration of effective inline analysis and purification tools is thereby frequently exploited to achieve effective and reliable flow processes. This perspective article summarizes recent applications of different inline purification techniques such as chromatography, extractions, and crystallization from academic and industrial laboratories. A discussion of the advantages and drawbacks of these tools is provided as a guide to aid researchers in selecting the most appropriate approach for future applications. It is hoped that this perspective contributes to new developments in this field in the context of process and cost efficiency, sustainability and industrial uptake of new flow chemistry tools developed in academia.

Application of reactor engineering concepts in continuous flow chemistry: a review

The adoption of flow technology for the manufacture of chemical entities, and in particular pharmaceuticals, has seen rapid growth over the past two decades with the technology now blurring the lines between chemistry and chemical engineering.

In-Line Purification: A Key Component to Facilitate Drug Synthesis and Process Development in Medicinal Chemistry

In-line purification is an important tool for flow chemistry. It enables effective handling of unstable intermediates and integration of multiple synthetic steps. The integrated flow synthesis is useful for drug synthesis and process development in medicinal chemistry. In this article, we overview current states of in-line purification methods. In particular, we focus on four common methods: scavenger column, distillation, nanofiltration, and extraction. Examples of their applications are provided.

Lattice-Boltzmann Simulation and Experimental Validation of a Microfluidic T-Junction for Slug Flow Generation

We investigate the interaction of two immiscible fluids in a head-on device geometry, where both fluids are streaming opposite to each other. The simulations are based on the two-dimensional (2D) lattice Boltzmann method (LBM) using the Rothman and Keller (RK) model. We validate the LBM code with several benchmarks such as the bubble test, static contact angle, and layered flow. For the first time, we simulate a head-on device by forcing periodicity and a volume force to induce the flow. From low to high flow rates, three main flow patterns are observed in the head-on device, which are dripping-squeezing, jetting-shearing, and threading. In the squeezing regime, the flow is steady and the droplets are equal. The jetting-shearing flow is not as stable as dripping-squeezing. Moreover, the formation of droplets is shifted downstream into the main channel. The last flow form is threading, in which the immiscible fluids flow parallel downstream to the outlet. In contrast to other studies, we select larger microfluidic channels with 1-mm channel width to achieve relatively high volumetric fluxes as used in chemical synthesis reactors. Consequently, the capillary number of the flow regimes is smaller than 10−5. In conclusion, the simulation compares well to experimental data.

A machine-assisted approach for the preparation of follow-on pharmaceutical compound libraries

Coupling of a continuous flow process to a robotic microwave device has led to a simple platform for the preparation of compound libraries, specifically the anti-migraine compound Zolmitriptan and several unknown analogues.

OpenFlowChem – a platform for quick, robust and flexible automation and self-optimisation of flow chemistry

OpenFlowChem – an open-access platform for automation of process control and monitoring optimised for flexibility.