One-Pot Synthesis of 2-Aryl-3-phenyl(benzyl)-5-phenylimino-Δ⁴-1,2,4-thiadiazolines usingN-Chlorosuccinimide

5‐Chloro‐3‐methylthio‐1,2,4‐thiadiazol‐2‐ium chlorides as useful synthetic precursors to a variety of 6aλ4‐thiapentalene systems

“…Literature synthetic pathways to analogous 5-iminothiadiazoles [4] mainly involved the oxidative cyclization of N-imidoylthioureas [18,19]. Hydrochloride derivatives proved to be rather stable heterocycles in contrast to their deprotonated counterparts, which underwent a rapid ring-opening process [18b].…”

The Synthesis of Aminobenzothiazoles from 2,3-Biaryl-5-anilino-Δ3-1,2,4-thiadiazolines

“…Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions 5-Amino-1,2,4-thiadiazoles, either in the form of salts (thiadiazolium salts 1) or free bases (thiadiazolines 2), can be synthesized from readily accessible amidinothioureas 3 using a variety of oxidizing agents such as elemental halogens, [2] N-chlorosuccinimide (NCS), [3] or diethyl azodicarboxylate (DEAD). [4] As shown in Sch.…”

“…[4] As shown in Sch. 1, when bromine [3,5] or N-bromosuccinimide (NBS) 3 were used as the oxidizing agents, 2-amidinobenzothiazoles 4 could be obtained at yields as high as 85%. Kurzer and Sanderson had reported the isomerization of 2-aryl-5-arylamino-3-arylimino-Á 3 -1,2,4-thiadiazolines5 to 2-guanidinobenzothiazoles 6.…”