Continuous-Flow Synthesis of (–)-Oseltamivir Phosphate (Tamiflu)

Rapid Multigram-Scale End-to-End Continuous-Flow Synthesis of Sulfonylurea Antidiabetes Drugs: Gliclazide, Chlorpropamide, and Tolbutamide

A multigram-scale robust, efficient, and safe end-to-end continuous-flow process for the diabetes sulfonylurea drugs gliclazide, chlorpropamide, and tolbutamide is reported. The drugs were prepared by the treatment of an amine with a haloformate affording carbamate, which was subsequently treated with a sulfonamide to afford sulfonylurea. Gliclazide was obtained in 87% yield within 2.5 minutes total residence time with 26 g/h throughput; 0.2 kg of the drug was produced in 8 hours of running the system continuously. Chlorpropamide and tolbutamide were both obtained in 94% yield within 1 minute residence time with 184–188 g/h throughput; 1.4–1.5 kg of the drugs was produced in 8 hours of running the system continuously. N-Substituted carbamates were used as safe alternatives to the hazardous isocyanates in constructing the sulfonyl urea moiety.

Cutting edge of diphenyl phosphorazidate (DPPA) as a synthetic reagent – A fifty-year odyssey

Recent developments of diphenyl phosphorazidate (DPPA, (C6H5O)2P(O)N3) has been reviewed.

Multistep Continuous Flow Synthesis of Stavudine

Herein, we demonstrate an elegant multistep continuous flow synthesis for stavudine (d4T), a potent nucleoside chemotherapeutic agent for human immunodeficiency virus, acquired immunodeficiency syndrome (AIDS) and AIDS-related conditions. This was accomplished via six chemical transformations in five sequential continuous flow reactors from an affordable starting material, 5-methyluridine. In the first instance, single step continuous flow synthesis was demonstrated with an average of 97% yield, 21.4 g/h throughput per step, and a total of 15.5 min residence time. Finally, multistep continuous flow synthesis of d4T in 87% total yield with a total residence time of 19.9 min and 117 mg/h throughput without intermediate purification was demonstrated.

Cluster Preface: Integrated Synthesis Using Continuous-Flow Technologies

Shinichiro Fuse was born in 1977 in Japan. He earned his B.S. degree in 2000 and his Ph.D. in 2005 from Tokyo Institute of Technology under the supervision of Prof. Takashi Takahashi. He was a researcher at ChemGenesis Incorporated between 2005 and 2006, and a postdoctoral fellow from 2006 to 2008 at Harvard University in the group of Prof. Daniel E. Kahne. In 2008, he joined the faculty at the Tokyo Institute of Technology as an assistant professor. He then moved to the Chemical Resources Laboratory at the same university as an associate professor in 2015. He was appointed as a professor at Nagoya University in 2019. His research is aimed toward the development of efficient synthetic processes based on a deep understanding of organic chemistry using flow synthesis, automated synthesis, theoretical calculations, and machine-learning technologies.

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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.