Diazo-Transfer Reagent 2-Azido-4,6-dimethoxy-1,3,5-triazine Displays Highly Exothermic Decomposition Comparable to Tosyl Azide

Sebastian P Green; Andrew D Payne; Katherine M Wheelhouse; Jason P Hallett; Philip W Miller; James A Bull

doi:10.1021/acs.joc.9b00269

Diazo-Transfer Reagent 2-Azido-4,6-dimethoxy-1,3,5-triazine Displays Highly Exothermic Decomposition Comparable to Tosyl Azide

J Org Chem. 2019 May 3;84(9):5893-5898. doi: 10.1021/acs.joc.9b00269. Epub 2019 Apr 17.

Authors

Sebastian P Green^{1

2}, Andrew D Payne³, Katherine M Wheelhouse⁴, Jason P Hallett², Philip W Miller¹, James A Bull¹

Affiliations

¹ Department of Chemistry, Molecular Sciences Research Hub , Imperial College London , White City Campus, 80 Wood Lane , London W12 0BZ , U.K.
² Department of Chemical Engineering , Imperial College London , South Kensington Campus, Exhibition Road , London SW7 2AZ , U.K.
³ Process Safety, Pilot Plant Operations, GlaxoSmithKline , GSK Medicines Research Centre , Gunnels Wood Road , Stevenage , Hertfordshire SG1 2NY , U.K.
⁴ API Chemistry, Product Development & Supply, GlaxoSmithKline , GSK Medicines Research Centre , Gunnels Wood Road , Stevenage , Hertfordshire SG1 2NY , U.K.

PMID: 30951630
DOI: 10.1021/acs.joc.9b00269

Abstract

2-Azido-4,6-dimethoxy-1,3,5-triazine (ADT) was reported recently as a new "intrinsically safe" diazo-transfer reagent. This assessment was based on differential scanning calorimetry data indicating that ADT exhibits endothermic decomposition. We present DSC data on ADT that show exothermic decomposition with an initiation temperature ( T_init) of 159 °C and an enthalpy of decomposition (Δ H_D) of -1135 J g^-1 (-207 kJ mol^-1). We conclude that ADT is potentially explosive and must be treated with caution, being of comparable exothermic magnitude to tosyl azide (TsN₃). A maximum recommended process temperature for ADT is 55 °C.