Automation of Synthesis in Medicinal Chemistry: Progress and Challenges

Since the 1990s, concerted attempts have been made to improve the efficiency of medicinal chemistry synthesis tasks using automation. Although impacts have been seen in some tasks, such as small array synthesis and reaction optimization, many synthesis tasks in medicinal chemistry are still manual. As it has been shown that synthesis technology has a large effect on the properties of the compounds being tested, this review looks at recent research in automation relevant to synthesis in medicinal chemistry. A common theme has been the integration of tasks, as well as the use of increased computing power to access complex automation platforms remotely and to improve synthesis planning software. However, there has been more limited progress in modular tools for the medicinal chemist with a focus on autonomy rather than automation.

Sustainable Synthesis of a Potent and Selective 5-HT7 Receptor Antagonist Using a Mechanochemical Approach

A mechanochemical procedure was developed to obtain PZ-1361, a potent and selective 5-HT₇ receptor antagonist, with antidepressant properties in rodents. The elaborated protocol offered several advantages over classical batch synthesis, including improvement of the overall yield (from 34% to 64%), reduction of reaction time (from 60 to 5.5 h), limitation of the use of toxic solvents, and the formation of byproducts. This approach represents a rare example of the synthesis of biologically active compounds exclusively performed using mechanochemical reactions.

Integrated Platform for Expedited Synthesis-Purification-Testing of Small Molecule Libraries

The productivity of medicinal chemistry programs can be significantly increased through the introduction of automation, leading to shortened discovery cycle times. Herein, we describe a platform that consolidates synthesis, purification, quantitation, dissolution, and testing of small molecule libraries. The system was validated through the synthesis and testing of two libraries of binders of polycomb protein EED, and excellent correlation of obtained data with results generated through conventional approaches was observed. The fully automated and integrated platform enables batch-supported compound synthesis based on a broad array of chemical transformations with testing in a variety of biochemical assay formats. A library turnaround time of between 24 and 36 h was achieved, and notably, each library synthesis produces sufficient amounts of compounds for further evaluation in secondary assays thereby contributing significantly to the shortening of medicinal chemistry discovery cycles.

A segmented flow platform for on-demand medicinal chemistry and compound synthesis in oscillating droplets

An automated flow chemistry platform performs single/multi-phase and single/multi-step chemistries in 14 μL droplets with online analysis and product collection.

A high-throughput synthesis of 1,2,4-oxadiazole and 1,2,4-triazole libraries in a continuous flow reactor

We report herein a high-throughput methodology for the synthesis of 1,2,4-oxadiazole and 1,2,4-triazole small-molecule libraries using an integrated synthesis and purification platform.