Optimizing thiadiazole analogues of resveratrol versus three chemopreventive targets
摘要:
Chemoprevention is an approach to decrease cancer morbidity and mortality through inhibition of carcinogenesis and prevention of disease progression. Although the trans stilbene derivative resveratrol has chemopreventive properties, its action is compromised by weak non-specific effects on many biological targets. Replacement of the stilbene ethylenic bridge of resveratrol with a 1,2,4-thiadiazole heterocycle and modification of the substituents on the two aromatic rings afforded potential chemopreventive agents with enhanced potencies and selectivities when evaluated as inhibitors of aromatase and NF-kappa B and inducers of quinone reductase 1 (QR1). (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of 1,2,4-Thiadiazoles by Oxidative Dimerization of Carbothioamides by Using Oxone
作者:Akira Yoshimura、Anthony D. Todora、Brent J. Kastern、Steven R. Koski、Viktor V. Zhdankin
DOI:10.1002/ejoc.201402756
日期:2014.8
1,2,4-Thiadiazoles were efficiently synthesized in good yields through the oxidative dimerization of carbothioamides by using Oxone as a readily available, inexpensive, and environmentally safe oxidant. A similar reaction of phenylselenoamide led to the corresponding 1,2,4-phenylselenadiazole in high yield.
unexpected thiazole 1B formation when 2,6‐dichlorobenzothioamide 1 and ethyl bromopyruvate were reacted under basic conditions at elevated temperatures in ethanol. Thiazole 1B, regio‐isomeric to that expected under conventional Hantzsch conditions, was extensively characterized and later confirmed by single crystal X‐ray structure. We carried out this transformation with several substituted benzothioamides and
A Mild and Efficient Synthesis of 2-Oxazolines via Transamidation–Cyclodehydrosulfurisation of Thioamides with 2-Aminoethanol
作者:Uma Pathak、D. Goud
DOI:10.1055/s-0032-1317341
日期:——
Transamidation of thioamides with 2-aminoethanol, followed by cyclodehydrosulfurisation of the resultant N-(beta-hydroxyethyl)thioamides, has been utilised for the mild and efficient synthesis of 2-oxazolines. The developed protocol was found to be of general applicability.
An unexpected synthesis of 3,5-diaryl-1,2,4-thiadiazoles from thiobenzamides and methyl bromocyanoacetate
作者:Abdelrahman S. Mayhoub、Evgeny Kiselev、Mark Cushman
DOI:10.1016/j.tetlet.2011.07.068
日期:2011.9
Aryl thioamides undergo very rapid condensation in the presence of methyl bromocyanoacetate to provide quantitative yields of 3,5-diaryl-1,2,4-thiadiazoles with an easy work-up and a high degree of product purity. The method can be scaled up with no loss in efficiency. (C) 2011 Elsevier Ltd. All rights reserved.