Facile synthesis of 3-aryl/alkylamino 5-aryl/alkyl 1,2,4-oxadiazoles from acylthiourea
摘要:
Facile and selective synthesis of 3-aryl/alkylamino 5-aryl/alkyl 1,2,4-oxadiazoles starting from N-acylthioureas has been demonstrated. The regio-selectivity is achieved by simply selecting an appropriate base used for the generation of hydroxyl amine from the corresponding hydrochloride salt. This method also avoids the use of toxic cyanogen bromide. The structure of the synthesized oxadiazoles has been resolved by tandem mass spectral studies. (C) 2011 Elsevier Ltd. All rights reserved.
Facile synthesis of 3-amino-5-aryl-1,2,4-oxadiazoles via PIDA-mediated intramolecular oxidative cyclization
作者:Kuan Lu、Liancheng Duan、Boxuan Xu、Weile Yin、Di Wu、Yanfang Zhao、Ping Gong
DOI:10.1039/c6ra08871f
日期:——
A mild and efficient method for the synthesis of 3-amino-5-aryl-1,2,4-oxadiazole by intramolecularcyclization using PhI(OAc)2 (PIDA) as an oxidant is developed. Various 3-amino-5-aryl-1,2,4-oxadiazoles are prepared in moderate to good yields, and the PIDA-mediated N–O bond formation mechanism is suggested. In view of the readily available starting materials, operational simplicity, high functionality
(3+2) Annulation of Amidinothioureas with Binucleophile: Synthesis and Antimicrobial Activity of 3-Phenylamino-5-aryl/alkyl-1,2,4-oxadiazole Derivatives
作者:Swapnil G. Yerande、Amruta B. Ghaisas、Kiran M. Newase、Wei Wang、Kan Wang、Alexander Dömling
DOI:10.1002/jhet.1873
日期:2014.11
efficient method for preparation of 3‐phenylamino‐5‐aryl/alkyl‐1,2,4‐oxadiazole by (3+2) annulation of amidinothioureas with binucleophilic hydroxylamine hydrochloride in the presence of mercury (II) chloride. Desired 3‐phenylamino‐5‐aryl/alkyl‐1,2,4‐oxadiazole was prepared in good to moderate yields. On the basis of the literature precedence, the mechanism for the formation of 3‐phenylamino‐5‐aryl/alkyl‐1
A Diversified Assembly of 1,2,4-Oxadiazol-3-amines: Metallic Thiophile Catalyzed Chemoselective One-Pot Reaction of Aryl Isothiocyanates, Amidines/Guanidines, and Hydroxylamine
作者:Kamala Vasu、Hitesh Jalani、V. Sudarsanam
DOI:10.1055/s-0032-1317504
日期:——
An efficient one-pot synthesis of 1,2,4-oxadiazol-3-amines from simple starting materials, isothiocyanates, amidines/guanidines, and hydroxylamine, is described. The reaction is facilitated by metallic-thiophile-assisted desulfurization of in situ formed amidino- or guanidinothiourea to give chemoselectively N-hydroxyguanidine intermediates that give exclusively various 1,2,4-oxadiazol-3-amines in good to excellent yields. The reaction mechanistic pathway may proceed through an intramolecular 5-exotrig cyclization.
Buscemi, Silvestre; Cicero, Maria G.; Vivona, Nicolo, Journal of Heterocyclic Chemistry, 1988, vol. 25, p. 931 - 935
作者:Buscemi, Silvestre、Cicero, Maria G.、Vivona, Nicolo、Caronna, Tullio