Daniela P. Gouvêa

Ultrasonics promoted synthesis of thiazolidinones from 2-aminopyridine and 2-picolilamine

The efficient multicomponent synthesis of thiazolidinones from the reaction of arenealdehydes, mercaptoacetic acid and 2-picolilamine or 2-aminopyridine under ultrasound irradiation are reported. The reaction with 2-aminopyridine needs a Lewis acid catalysis to afford the corresponding 2-aryl-3-(pyridin-2-yl)-1,3-thiazolidin-4-ones. All novel compounds were identified and characterized by (1)H and (13)C NMR spectra. Applying the sonochemical methodology, two series of heterocyclic thiazolidinones were synthesized in good yields after short reaction times.

7-chloroquinolin-4-yl arylhydrazone derivatives: synthesis and antifungal activity.

Fifteen 7-chloro-4-arylhydrazonequinolines have been evaluated for their in vitro antifungal activity against eight oral fungi: Candida albicans, C. parapsilosis, C. lipolytica, C. tropicalis, C. famata, C. glabrata, Rhodutorula mucilaginosa, and R. glutinis. Several compounds exhibited minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) activities comparable with the first-line drug fluconazole. These results could be considered as an important starting point for the rational design of new antifungal agents.

Efficient Synthesis and Antioxidant Evaluation of 2-Aryl-3-(Pyrimidin-2-yl)-Thiazolidinones

In the present study, we reported the efficient synthesis of 11 3‐(pyrimidin‐2‐yl)‐thiazolidinones in good yields using molecular sieve as the desiccant agent. In addition, we have evaluated the antioxidant capacity of the synthesized compounds by the 2,2‐diphenyl‐2‐picrylhydrazyl hydrate (DPPH•) and the 2,2‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) diammonium salt (ABTS+•) radicals scavenging assay. Six compounds showed antioxidant activity towards DPPH• (EC50 between 16.13 and 49.94 µg/mL) and also demonstrated excellent activity regarding ABTS+• (TEAC: 10.32–53.52). These results showed that compounds 3‐(pyrimidin‐2‐yl)‐thiazolidinones may be easily synthesized by a less expensive procedure and could be a good starting point to the development of new antioxidant compounds.

Synthesis of Novel 2-Aryl-3-(2-morpholinoethyl)-1,3-thiazinan-4-ones Via Ultrasound Irradiation

This study describes the synthesis of fourteen thiazinanones from a multicomponent reaction of 2-morpholinoehtylamine (as primary amine), arenealdehydes (as carbonyl compound) and the mercaptopropionic acid using both conventional (thermal heating) and ultrasound methodologies. Through thermal heating methodology, the thiazinanones were obtained in 49 to 97% yields for 16 hours and through sonochemistry methodology, the reaction time was reduced for 25 minutes with yields 41 to 88%. The full identification and characterization of unpublished heterocycles were achieved by proton (1H) and carbon 13 (13C) nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and infrared. Some of them were also characterized by elemental analysis.

Thiazolidin-4-ones from 3-(Aminomethyl)pyridine, Arenealdehydes and Mercaptoacetic Acid: Synthesis and Radical Scavenger Activity

The efficient synthesis of fifteen novel thiazolidin-4-ones from reaction of 3-(aminomethyl) pyridine (3-picolylamine), arenealdenhydes and mercaptoacetic acid was described. The desired compounds were obtained in moderated to good yields by two methodologies: conventional heating and ultrasound irradiation. The thiazolidin-4-ones were fully identified and characterized by nuclear magnetic resonance (NMR), gas chromatography coupled to mass spectrometry (GC‑MS) and high resolution mass spectrometry (HRMS) techniques. Four compounds showed radical scavenger activity in the 2,2’-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) assay.

Ovicidal in vitro activity of 2-aryl-3-(2-morpholinoethyl)thiazolidin-4-ones and 2-aryl-3-(3-morpholinopropyl)thiazolidin-4-ones against Fasciola hepatica (Linnaeus, 1758)

Although there is a variety of biological activity reports regarding compounds derived from thiazolidin-4-ones, no data related to ovicidal activity against trematodes, particularly Fasciola hepatica are available. Since there are reports about anthelmintic resistance in F. hepatica, new drugs are required. Thus, this study evaluated ovicidal action in vitro against F. hepatica eggs in two systematic series of thiazolidin-4-ones: 2-aryl-3-(2-morpholinoethyl)thiazolidin-4-ones (1a-h) and 2-aryl-3-(3-morpholinopropyl)thiazolidin-4-ones (2a-h) at different concentrations (20, 2, 0.2, 0.02 and 0.002 μg/ml). The egg hatch assay (EHA) was used to evaluate the ovicidal action property of such compounds. In addition, potential negative effects of the compounds on metabolic activity of bovine kidney (MDBK) cells were evaluated by determining mitochondrial dehydrogenase activity. The eggs used in the EHA were obtained from parasites removed from the liver of cattle, which were discarded by slaugh after sanitary inspection. The results of EHA showed that compounds 2a-h exhibited ovicidal activity, especially compounds 2b which showed 90% ovicidal activity and viability of 93% MDBK cells at the concentration of 2 μg/ml; and 2e with 96-99% ovicidal activity at 0.2 μg/ml, 0.02 μg/ml and 0.002 μg/ml. The results show the potential of compound 2b to continue the studies in the production of new compounds with anthelmintic action.

Variable intermolecular interactions in 2-aryl-3-(pyridin-2-yl)-1,3-thiazolidin-4-one derivatives

Abstract The crystal structures of a number of racemic 2-(XC6H4)-3-(pyridin-2-yl)-1,3-thiazolidinon-4-one derivatives (1: X = 4-Me, 4-CN, 3-CN, 3-NO2, 3-F and 2-F), are reported. The thiazolidinone rings are non-planar arising from a twist about a S-C bond or from the sulphur atom being displaced from the plane of the other atoms. Apart from (1: X = 4-CN), the phenyl ring is near orthogonal to both the pyridyl and thiazolidinonyl rings. In the absence of strong classical intermolecular interactions, the supramolecular arrangements are generated from combinations of some of C-H ... X (X =O, N, F), C-X ... π (X = H, F) and π ... π interactions. Apart from (1: X = 4-Me), the substituent X is involved in the intermolecular connections in each case. The two fluoro derivatives, (1: X = 2-F) and (1: X = 3-F), exhibit similar sets of interactions, i.e., C-H ... X (X =O and N), C-X ... π(pyridyl) (X = H and F), and C-H ... π(phenyl) interactions, with (1: X = 3-F) also possessing C-H ... F hydrogen bonds. For the two cyano derivatives, (1: X = 3-CN) and (1: X = 4-CN), common interactions are C-H ... X (X = O and N) hydrogen bonds and π ... π stacking interactions. All three oxygens in (1: X = 3-NO2) are involved in C-H ... O, hydrogen bonds with additional C-H ... π and π ... π interactions also present. The supramolecular arrangements vary considerably in each case. The dimensionality of the structures vary from one, for (1: X = 4-Me) where only C-H ... π(phenyl) interactions are present, to three dimensional for the others.

Efficient multicomponent synthesis of thiazolidinones from 2- aminoethyl(propyl)morpholine

The ultrasound irradiation has generated beneficial effects in chemical processes, particularly in cases where traditional methods need prolonged reaction times. In continuation of our work 4 , the aim of this paper is synthesis of five-membered heterocyclic thiazolidinones from the cyclocondensation reaction of 2-aminoethyl(propyl)morpholine, arenealdehydes and mercaptoacetic acid by conventional and sonochemistry methodologies.