Related Experiment Video
Updated: Sep 28, 2026

Continuous Flow Chemistry: Reaction of Diphenyldiazomethane with p-Nitrobenzoic Acid
Published on: November 15, 2017
DYNO-MILL Mechanochemistry Enables Diaziridine-Mediated Access to Unsymmetrical Azobenzenes and Electrochemical
1Department of Chemistry, School of Natural Sciences, Shiv Nadar Institution of Eminence, Deemed to be University, Dadri, Uttar Pradesh, India.
Abstract:
We report a catalyst-, acid-, and base-free strategy for activation of an N-N-containing diaziridine/diazo-derived framework enabling the synthesis of unsymmetrical azobenzenes via a mechanochemical three-component reaction in a horizontal bead mill (DYNO-MILL). The process proceeds through in situ formation of a diaziridine intermediate from a formal 2 + 1 annulation of diazo esters and dialkyl azodicarboxylates, followed by electrophile-induced N─N bond reorganization with aryl diazonium tetrafluoroborates. This solvent-minimized, operationally simple protocol tolerates air and moisture and is scalable. The resulting azobenzenes serve as versatile substrates for oxidant-free electrochemical conversion to substituted tetrazoles without chromatographic purification. Green metrics analysis for the tetrazole formation reveals a significant improvement in atom economy (77.33%) compared to literature methods (29.98%-34.96%) and an enhanced Eco-Scale score (73), highlighting the sustainability of this approach.
Related Concept Videos
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Carboxylic Acids to Methylesters: Alkylation using Diazomethane
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo, or cyano...

