S1 Supporting Information Investigating Triorthogonal Chemoselectivity. Effect of Azide Substitution on the Triazine Core Anamika Sharma, 1,2 Rotimi Sheyi, 1 Ashish Kumar, 1 Ayman El-Faham, 3,4 Beatriz G. de la Torre, 2 Fernando Albericio 1,3,5 1 Peptide Science Laboratory, School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa 2 KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa 3 Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia 4 Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Alexandria 21321, Egypt 5 CIBER-BBN (Networking Centre on Bioengineering, Biomaterials and Nanomedicine) and Department of Organic Chemistry. University of Barcelona, 08028 Barcelona, Spain Email: albericio@ukzn.ac.za Table of Contents 1 General information : S2 2 General procedure for synthesis of mono substituted triazine (m-TA) derivatives : S2 3 General procedure for synthesis of dichloro substituted TA (d-TA) derivatives : S4 4 Synthesis of tri-substituted s-triazine from above precursors : S7 5 Characterization of synthesized derivatives : S9 6 Cartesian coordinates for NBO calculations : S45