Synthesis of Mepivacaine and Its Analogues by a Continuous-Flow Tandem Hydrogenation/Reductive Amination Strategy

Development of the telescoped flow Pd-catalyzed aerobic alcohol oxidation/reductive amination sequence in the synthesis of new phosphatidylinositide 3-kinase inhibitor (CPL302415)

Herein, we describe a two-step sequential flow synthesis: Pd-catalyzed aerobic oxidation to an aldehyde 2, which is then converted by reductive amination in H-Cube® PRO into CPL302415 (3). CPL302415 is our new PI3Kδ inhibitor, which is now under evaluation for the treatment of systemic lupus erythematosus. The process was optimized using the DoE approach and generalized to other biologically active derivatives of CPL302415.

A new strategy for immobilization of copper on the Fe3O4@EDTA nanocomposite and its efficient catalytic applications in reduction and one-pot reductive acetylation of nitroarenes and also N-acetylation of arylamines

A new and efficient Cu(II)-containing mesoporous nanocatalytic system was synthesized by direct immobilization of copper metal powder on the Fe3O4@EDTA nanocomposite. The as-prepared Fe3O4@EDTA@Cu(II) nanocomposite was then characterized by FT-IR, XRD, SEM, TEM, SEM-based EDX and elemental mapping, XPS, TGA, VSM, and also BET and BJH analyses. The resulting Fe3O4@EDTA@Cu(II) mesoporous nanocomposite exhibited satisfactory catalytic activity towards the reduction and one-pot reductive acetylation of nitroarenes and also N-acetylation of arylamines in water at 60 °C. Notably, the applied Cu(II)-containing nanocatalyst was efficiently recovered from the reaction mixture using an external magnetic field and could be reused successfully for five cycles. The protocol developed in this study offers several advantages in terms of mild reaction conditions, simple workflows, using water as a green solvent, and easy recovery and catalyst reuse, making it more ecologically and economically attractive.

Rapid production of the anaesthetic mepivacaine through continuous, portable technology

Local anaesthetics such as mepivacaine are key molecules in the medical sector, so ensuring their supply chain is crucial for every health care system. Rapid production of mepivacaine from readily available commercial reagents and (non-dry) solvents under safe conditions using portable, continuous apparatus could make an impactful difference in underdeveloped countries. In this work, we report a continuous platform for synthesising mepivacaine, one of the most widely used anaesthetics for minor surgeries. With a focus on sustainability, reaction efficiency and seamless implementation, this platform afforded the drug in 44% isolated yield following a concomitant distillation-crystallisation on a gram scale after N-functionalisation and amide coupling, with full recovery of the solvents and excess reagents. The use of flow chemistry as an enabling tool allowed the use of "forbidden" chemistry which is typically challenging for preparative and large scale reactions in batch mode. Overall, this continuous platform presents a promising and sustainable approach that has the potential to meet the demands of the healthcare industry.

3D printing and continuous flow chemistry technology to advance pharmaceutical manufacturing in developing countries

The realization of a downward spiralling of diseases in developing countries requires them to become self-sufficient in pharmaceutical products. One of the ways to meet this need is by boosting the local production of active pharmaceutical ingredients and embracing enabling technologies. Both 3D printing and continuous flow chemistry are being exploited rapidly and they are opening huge avenues of possibilities in the chemical and pharmaceutical industries due to their well-documented benefits. The main barrier to entry for the continuous flow chemistry technique in low-income settings is the cost of set-up and maintenance through purchasing of spare flow reactors. This review article discusses the technical considerations for the convergence of state-of-the-art technologies, 3D printing and continuous flow chemistry for pharmaceutical manufacturing applications in developing countries. An overview of the 3D printing technique and its application in fabrication of continuous flow components and systems is provided. Finally, quality considerations for satisfying regulatory requirements for the approval of 3D printed equipment are underscored. An in-depth understanding of the interrelated aspects in the implementation of these technologies is crucial for the realization of sustainable, good quality chemical reactionware.

Recent Progress in Continuous-Flow Hydrogenation

To achieve a safe, efficient, and sustainable (even fully automated) production for the continuous-flow hydrogenation reactions, which is among the most often used reactions in chemical synthesis, new catalyst types and immobilization methods as well as flow reactors and technologies have been developed over the last years; in addition, these approaches have been combined with new and transformational technologies in other fields such as artificial intelligence. Thus, attention from academic and industry practitioners has increasingly focused on improving the performance of hydrogenation in flow mode by reducing the reaction times, increasing selectivities, and achieve safe operation. This Minireview aims to summarize the most recent research results on this topic with focus on the advantages, current limitations, and future directions of flow chemistry.

Reworking Organic Synthesis for the Modern Age: Synthetic Strategies Based on Continuous-Flow Addition and Condensation Reactions with Heterogeneous Catalysts

While organic synthesis carried out in most laboratories uses batch methods, there is growing interest in modernizing fine chemical synthesis through continuous-flow processes. As a synthetic method, flow processes have several advantages over batch systems in terms of environmental compatibility, efficiency, and safety, and recent advances have allowed for the synthesis of several complex molecules, including active pharmaceutical ingredients (APIs). Nevertheless, due to several reasons related to the difficulties arising from byproduct formation during the flow process, such as lower yields, poor selectivities, clogging of columns due to poor solubility, catalyst poisoning, etc., successful examples of continuous-flow synthesis of complex organic molecules are still limited. In order to solve this bottleneck, the development of selective and atom-economical continuous-flow organic transformations are needed. This perspective highlights examples of atom-economical addition and condensation reactions with heterogeneous catalysts under continuous-flow conditions and their applications for the synthesis of complex organic molecules such as natural products and APIs. In order to realize new continuous-flow methodologies, based on addition and condensation reactions, in place of substitution reactions, the development of novel reactions and heterogeneous catalysts is required.

Evolution of flow-oriented design strategies in the continuous preparation of pharmaceuticals

This review focuses on the flow-oriented design (FOD) in the multi-step continuous-flow synthesis of active pharmaceutical ingredients.

Reductive Amination in the Synthesis of Pharmaceuticals

Reductive amination plays a paramount role in pharmaceutical and medicinal chemistry owing to its synthetic merits and the ubiquitous presence of amines among biologically active compounds. It is one of the key approaches to C-N bond construction due to its operational easiness and a wide toolbox of protocols. Recent studies show that at least a quarter of C-N bond-forming reactions in the pharmaceutical industry are performed via reductive amination. This Review concisely compiles information on 71 medical substances that are synthesized by reductive amination. Compounds are grouped according to the principle of action, which includes drugs affecting the central nervous system, drugs affecting the cardiovascular system, anticancer drugs, antibiotics, antiviral and antifungal medicines, drugs affecting the urinary system, drugs affecting the respiratory system, antidiabetic medications, drugs affecting the gastrointestinal tract, and drugs regulating metabolic processes. A general synthetic scheme is provided for each compound, and the description is focused on reductive amination steps. The green chemistry metric of reaction mass efficiency was calculated for all reactions.

Flow-oriented synthetic design in the continuous preparation of the aryl piperazine drug flibanserin

The first integrated continuous-flow synthesis of the drug substance flibanserin was developed, using an uninterrupted four-step sequence, via an unprecedented route.

Continuous-flow protocol for the synthesis of enantiomerically pure intermediates of anti epilepsy and anti tuberculosis active pharmaceutical ingredients

Continuous-flow production of chiral intermediates plays an important role in the development of building blocks for Active Pharmaceutical Ingredients (APIs), being α-amino acids and their derivatives widely applied as building blocks.

7-Step Flow Synthesis of the HIV Integrase Inhibitor Dolutegravir

Dolutegravir (DTG), an important active pharmaceutical ingredient (API) used in combination therapy for the treatment of HIV, has been synthesized in continuous flow. By adapting the reported GlaxoSmithKline process chemistry batch route for Cabotegravir, DTG was produced in 4.5 h in sequential flow operations from commercially available materials. Key features of the synthesis include rapid manufacturing time for pyridone formation, one-step direct amidation of a functionalized pyridone, and telescoping of multiple steps to avoid isolation of intermediates and enable for greater throughput.