An alternatively metal-free synthesis of 1,3,5-triazines or 1,2,4-thiadiazoles from benzyl chlorides and benzylamines mediated by elemental sulfur

An elemental sulfur mediated reaction of benzyl chlorides with benzylamines is developed, which allows the practical synthesis of valuable 1,3,5-triazines. This protocol that is metal free, ligand free, and uses inexpensive elemental sulfur as oxidant or raw material displays mild reaction conditions, a broad substrate scope and moderate to good yields. Moreover, the modified sulfur-mediated reaction system can also be used to synthesize 1,2,4-thiadiazoles, by simply switching the stoichiometry of sulfur powder from 0.75 equivalents to 5 equivalents. (C) 2019 Elsevier Ltd. All rights reserved.