Volume 8, Issue 3 p. 504-512
Full Paper

Pressure-Accelerated Azide–Alkyne Cycloaddition: Micro Capillary versus Autoclave Reactor Performance

Svetlana Borukhova

Svetlana Borukhova

Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process Technology, Eindhoven University of Technology, Den Dolech 2, 5612AZ, Eindhoven (The Netherlands)

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Dr. Andreas D. Seeger

Dr. Andreas D. Seeger

Technische Chemie III, Technische Universität Darmstadt, Alarich-Weiss-Straße 8, 64287 Darmstadt (Germany)

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Dr. Timothy Noël

Dr. Timothy Noël

Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process Technology, Eindhoven University of Technology, Den Dolech 2, 5612AZ, Eindhoven (The Netherlands)

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Qi Wang

Qi Wang

Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process Technology, Eindhoven University of Technology, Den Dolech 2, 5612AZ, Eindhoven (The Netherlands)

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Prof. Dr. Markus Busch

Prof. Dr. Markus Busch

Technische Chemie III, Technische Universität Darmstadt, Alarich-Weiss-Straße 8, 64287 Darmstadt (Germany)

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Prof. Dr. Volker Hessel

Corresponding Author

Prof. Dr. Volker Hessel

Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process Technology, Eindhoven University of Technology, Den Dolech 2, 5612AZ, Eindhoven (The Netherlands)

Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process Technology, Eindhoven University of Technology, Den Dolech 2, 5612AZ, Eindhoven (The Netherlands)Search for more papers by this author
First published: 17 December 2014
Citations: 18

Graphical Abstract

Press to access! The potential of pressure in chemical intensification of intrinsic kinetics of 1,3-dipolar cycloaddition is investigated along with high temperature and concentration effects. Two reactors are compared, a specialized autoclave batch reactor for high-pressure operation up to 1800 bar and a capillary flow reactor for up to 400 bar. Reaction speedup and increases in space-time yields are reached while widening process windows of favorable operation to selectively produce Rufinamide precursor in good yields.

Abstract

Pressure effects on regioselectivity and yield of cycloaddition reactions have been shown to exist. Nevertheless, high pressure synthetic applications with subsequent benefits in the production of natural products are limited by the general availability of the equipment. In addition, the virtues and limitations of microflow equipment under standard conditions are well established. Herein, we apply novel-process-window (NPWs) principles, such as intensification of intrinsic kinetics of a reaction using high temperature, pressure, and concentration, on azide–alkyne cycloaddition towards synthesis of Rufinamide precursor. We applied three main activation methods (i.e., uncatalyzed batch, uncatalyzed flow, and catalyzed flow) on uncatalyzed and catalyzed azide–alkyne cycloaddition. We compare the performance of two reactors, a specialized autoclave batch reactor for high-pressure operation up to 1800 bar and a capillary flow reactor (up to 400 bar). A differentiated and comprehensive picture is given for the two reactors and the three methods of activation. Reaction speedup and consequent increases in space–time yields is achieved, while the process window for favorable operation to selectively produce Rufinamide precursor in good yields is widened. The best conditions thus determined are applied to several azide–alkyne cycloadditions to widen the scope of the presented methodology.