One-pot synthesis of 1,3-thiazolidin-4-one using ammonium persulfate as catalyst

Application of a novel deep eutectic solvent as a capable and new catalyst for the synthesis of tetrahydropyridines and 1,3-thiazolidin-4-ones

A novel deep eutectic solvent (ETPP-Br/THF-TCA-DES) was prepared by a mixture of ethyl triphenylphosphonium bromide (ETPP-Br) and tetrahydrofuran-2,3,4,5-tetra-carboxylic acid (THF-TCA, mole ratio 7:3), characterized by FT-IR, TGA/DTA, densitometer, eutectic point, and ¹H NMR techniques and used as a capable and new catalyst for the synthesis of two sets of compounds: (1) the four new [a(1-4)] and the eleven [a(5-15)] known alkyl 1,2,6-trisubstituted-4-[(hetero)arylamino]-1,2,5,6-tetrahydropyridine-3-carboxylates and (2) the two new [b(1-2)] and the eight [b(3-10)] known 1,3-thiazolidin-4-ones in DES with short reaction time, high yields, and easy recycling and separation of the DES catalyst. There is a nice consistency between the proposed structure of the DES compound, the integration values of the ¹H NMR peaks and the ratio of ETPP-Br to THF-TCA obtained from the eutectic point phase diagram. Also, the decrease in splitting patterns of the peaks in DES, compared to the two starting materials can be the good evidence of the hydrogen bond formation between the two components.

α-Aminoazoles/azines: key reaction partners for multicomponent reactions

Aromatic α-aminoazaheterocycles are the focus of significant investigations and exploration by researchers owing to their key role in diverse biological and physiological processes. The existence of their derivatives in numerous drugs and alkaloids is due to their heterocyclic nitrogenous nature. Therefore, the synthesis of a structurally diverse range of their derivatives through simple and convenient methods represents a vital field of synthetic organic chemistry. Multicomponent reactions (MCRs) provide a platform to introduce desirable structure diversity and complexity into a molecule in a single operation with a significant reduction in the use of harmful organic waste, and hence have attracted particular attention as an excellent tool to access these derivatives. This review covers the advances made from 2010 to the beginning of 2020 in terms of the utilization of α-aminoazaheterocycles as synthetic precursors in MCRs.

Design of a new multi-functional catalytic system Ni/SO3H@zeolite-Y for three-component synthesis of N-benzo-imidazo- or -thiazole-1,3-thiazolidinones

In this investigation, a nanoporous zeolite-NaY supported sulfonic acid was synthesized and Ni(ii) ions were successfully stabilized on SO₃H@zeolite-Y (Ni/SO₃H@zeolite-Y). This novel type of zeolitic nanocomposite was characterized using various techniques including FT-IR, FE-SEM, TGA, BET and EDX. Ni/SO₃H@zeolite-Y was used as a multi-functional and highly active nanocatalyst for the three-component synthesis of 3-benzimidazolyl-1,3-thiazolidin-4-ones and new 3-benzthiazoleyl-1,3-thiazolidin-4-ones via cyclocondensation of 2-aminobenzimidazole or 2-aminobenzothiazole, aromatic aldehydes and thioglycolic acid in acetone-H₂O at room temperature. This economical chemical procedure has advantages such as excellent yield in short reaction times, convenient manipulation and high purity of products, applicability to a broad range of substrates, and the use of a nontoxic and heterogeneous acid catalyst with good reusability.

Saturated Five-Membered Thiazolidines and Their Derivatives: From Synthesis to Biological Applications

In past decades, interdisciplinary research has been of great interest for scholars. Thiazolidine motifs behave as a bridge between organic synthesis and medicinal chemistry and compel researchers to explore new drug candidates. Thiazolidine motifs are very intriguing heterocyclic five-membered moieties present in diverse natural and bioactive compounds having sulfur at the first position and nitrogen at the third position. The presence of sulfur enhances their pharmacological properties, and, therefore, they are used as vehicles in the synthesis of valuable organic combinations. They show varied biological properties viz. anticancer, anticonvulsant, antimicrobial, anti-inflammatory, neuroprotective, antioxidant activity and so on. This diversity in the biological response makes it a highly prized moiety. Based on literature studies, various synthetic approaches like multicomponent reaction, click reaction, nano-catalysis and green chemistry have been employed to improve their selectivity, purity, product yield and pharmacokinetic activity. In this review article, we have summarized systematic approaches for the synthesis of thiazolidine and its derivatives, along with their pharmacological activity, including advantages of green synthesis, atom economy, cleaner reaction profile and catalyst recovery which will help scientists to probe and stimulate the study of these scaffolds.

SO3H-functionalized Zeolite-Y as an Efficient Nanocatalyst for the Synthesis of Nbenzimidazole- 2-aryl-4-thiazolidinones and tri-substituted Imidazoles

BACKGROUND

SO3H-functionalized zeolite-Y was prepared and used as a catalyst for the synthesis of 2-aryl-N-benzimidazole-4-thiazolidinones and tri-substituted imidazoles at ambient conditions.

OBJECTIVE

The goals of this catalytic method include excellent yields and high purity, inexpensive procedure and ease of product isolation, the use of nontoxic and heterogeneous acid catalyst, shorter reaction times and milder conditions.

MATERIALS AND METHODS

NMR spectra were recorded on Brucker spectrophotometer using Me4Si as internal standard. Mass spectra were recorded on an Agilent Technology 5975C VL MSD with tripe-axis detector. FTIR spectra were obtained with KBr disc on a galaxy series FT-IR 5000 spectrometer. The surface morphology of nanostructures was analyzed by FE-SEM (EVO LS 10, Zeiss, Carl Zeiss, Germany). BET analysis were measured at 196 °C by a Japan Belsorb II system after the samples were vacuum dried at 150°C overnight.

RESULTS

The NSZ was characterized by FT-IR, FESEM, EDX, XRF, and BET. The catalytic activity of NSZ was investigated for synthesis of 1,3-tiazolidin-4-ones in H2O/Acetone at room temperature. Moreover, NSZ was used for synthesis of tri-substituted imidazoles at 60 °C via solvent-free condensation. Different kinds of aromatic aldehydes were converted to the corresponding of products with good to excellent yields.

CONCLUSION

Sulfonated zeolite-Y was as an efficient catalyst for the preparation of N-benzimidazole-2-aryl-1,3- thiazolidin-4-ones and 2,4,5-triaryl-1H-imidazoles. High reaction rates, elimination toxic solvent, simple experimental procedure and reusability of the catalyst are the important features of this protocol.

Aminoazole-Based Diversity-Oriented Synthesis of Heterocycles

The comprehensive review contains the analysis of literature data concerning reactions of heterocyclization of aminoazoles and demonstrates the application of these types of transformations in diversity-oriented synthesis. The review is oriented to wide range of chemists working in the field of organic synthesis and both experimental and theoretical studies of nitrogen-containing heterocycles.