Synthesis of 5-substituted 1H-tetrazoles from nitriles and hydrazoic acid by using a safe and scalable high-temperature microreactor approach.

Interest in tetrazole chemistry over the past few years has been increasing rapidly, mainly as a result of the role played by this heterocyclic functionality in medicinal chemistry as a metabolically stable surrogate for carboxylic acid functionalities. Additional important applications for tetrazoles are found in coordination chemistry, materials science, and as intermediates in a variety of synthetic transformations. The most common synthetic approach to prepare 5-substituted 1H-tetrazole derivatives involves the addition of azide salts to organic nitriles in a temperature range of typically 100–150 8C (Scheme 1). A plethora of synthetic

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