ZnCl2 catalyzed efficient synthesis of 1,3,4-oxadiazole and 1,3,4-thiadiazole
摘要:
New methods for the synthesis of 1,3,4-oxadiazole and 1,3,4-thiadiazole have been described. No cyclizations took place in the absence of ZnCl2. 1,3,4-Thiadiazoles are formed in the presence of ZnCl2 alone, whereas oxadiazoles are produced when a base such as Et3N or KOH was used along with ZnCl2. % Yields are optimized. (C) 2014 Elsevier Ltd. All rights reserved.
New Method of 4,5-Disubstituted 1,2,4-triazolo-3-thiones Synthesis
摘要:
A universal method of 4,5-disubstituted S-triazolo-3-thiones synthesis from methyl esters of arylothiocarbazoic acids and some primary amines is presented.
The novel 1,2,4-triazole derivatives have been synthesized by a few different pathways. Heterocyclic carbohydrazides were used to obtain monoesters of hydrazine acids (1-6), thiosemicarbazide derivatives (7-17), and finaly 1,2,4-triazole-5-thiones (18-38). Carbohydrazides were also cyclized with methyl carbamodithioates in the presence of DBU giving 1,2,4-triazole-5-thiones (18, 19, 39-47). Two of final products (39, 40) were undergone alkylation in alkaline solution to appropriate sulfides (48-53). Then methylsulfides (48, 49) were oxidized with peroxyacetic acid to sulfoxides (54, 55). The obtained compounds were tested in vitro towards Mycobacterium tuberculosis.
New Method of 4,5-Disubstituted 1,2,4-triazolo-3-thiones Synthesis
作者:Henryk Foks、Barbara Milczarska
DOI:10.1080/104265090508217
日期:2005.1.1
A universal method of 4,5-disubstituted S-triazolo-3-thiones synthesis from methyl esters of arylothiocarbazoic acids and some primary amines is presented.
ZnCl2 catalyzed efficient synthesis of 1,3,4-oxadiazole and 1,3,4-thiadiazole
作者:Md.A. Rahman、Mohammad R. Karim、Md. Arifuzzaman、Tasneem A. Siddiquee、Aminul H. Mirza
DOI:10.1016/j.tetlet.2014.04.046
日期:2014.5
New methods for the synthesis of 1,3,4-oxadiazole and 1,3,4-thiadiazole have been described. No cyclizations took place in the absence of ZnCl2. 1,3,4-Thiadiazoles are formed in the presence of ZnCl2 alone, whereas oxadiazoles are produced when a base such as Et3N or KOH was used along with ZnCl2. % Yields are optimized. (C) 2014 Elsevier Ltd. All rights reserved.