One-pot sequential synthesis of tetrasubstituted thiophenes via sulfur ylide-like intermediates.

Herein, we describe a novel approach for the practical synthesis of tetrasubstituted thiophenes 8. The developed method was particularly used for the facile preparation of thienyl heterocycles 8. The mechanism for this reaction is based on the formation of a sulfur ylide-like intermediate. It was clearly suggested by (i) the intramolecular cyclization of ketene N,S-acetals 7 to the corresponding thiophenes 8, (ii) 1H NMR studies of Meldrum's acid-substituted aminothioacetals 9, and (iii) substitution studies of the methoxy group on Meldrum's acid containing N,S-acetals 9b. Notably, in terms of structural effects on the reactivity and stability of sulfur ylide-like intermediates, 2-pyridyl substituted compound 7a exhibited superior properties over those of others.

Discovery of tetrasubstituted thiophenes as Cisd2 activators: A potential novel therapeutic option in nonalcoholic fatty liver disease.

Down-regulation of Cisd2 in the liver has been implicated in the development of nonalcoholic fatty liver disease (NAFLD) and increasing the level of Cisd2 is therefore a potential therapeutic approach to this group of diseases. Herein, we describe the design, synthesis, and biological evaluation of a series of Cisd2 activators, all thiophene analogs, based on a hit obtained using two-stage screening and prepared via either the Gewald reaction or by intramolecular aldol-type condensation of an N,S-acetal. Metabolic stability studies of the resulting potent Cisd2 activators suggest that thiophenes 4q and 6 are suitable for in vivo studies. The results from studies on 4q-treated and 6-treated Cisd2hKO-het mice, which carry a heterozygous hepatocyte-specific Cisd2 knockout, confirm that (1) there is a correlation between Cisd2 levels and NAFLD and (2) these compounds have the ability to prevent, without detectable toxicity, the development and progression of NAFLD.

Synthesis and Biological Evaluation of Novel 2-(4-acetyl-3-methyl- 5-(arylamino) thiophen-2-yl)-3-arylquinazolin-4(3H)-one Derivatives as Potential Anti-inflammatory and Antioxidant Agents.

BACKGROUND: A new series of 2-(4-acetyl-3-methyl-5-(arylamino) thiophen-2- yl)-3-arylquinazolin-4(3H)-one derivatives (11a-11j) were synthesized from acetyl acetone, phenyl isothiocyanate and 2-chloromethyl quinazolinone. OBJECTIVE: Due to side effects of Non Steroidal Anti-Inflammatory Drugs (NSAID), an attempt was made to identify the novel tetrasubstituted thiophene lead compound as potential anti-inflammatory and antioxidant agent. METHODS: Then newly synthesized compounds were characterized by IR spectroscopy, 1H NMR and mass spectrometry. The synthesized compounds were screened for their in vivo anti-inflammatory activity in carrageenan-induced rat hind paw edema model at dose 20mg/kg body weight using diclofenac sodium as a standard drug. The compounds were also evaluated for their in vitro DPPH free radical-scavenging activity and nitric oxide radical scavenging activity at the concentrations of 10, 20, 40, 60, 80 and 100 µg/mL using ascorbic acid as standard drug. RESULTS: The results from carrageenan-induced rat hind paw edema showed that compounds 11e, 11f and 11b show a significant anti-inflammatory activity of 46.61%, 48.94% and 47.04 % protection respectively to inflamed paw but less than diclofenac sodium. Compounds 11h and 11e show good DPPH free radical scavenging and nitric oxide radical scavenging activity, respectively. CONCLUSION: From results, it was observed that highly substituted thiophene scaffold exhibits anti-inflammatory and antioxidant activity.