A novel synthesis of some 2‐imino‐4‐thiazolidinone derivatives

An efficient and simple route is presented to the synthesis of some iminothiazolidinone derivatives. α‐Chloro amide derivatives undergo coupling reaction with isothiocyanate in the presence of a mild base, followed by nucleophilic substitution of chlorine by the sulfur atom of isothiocyanate.     

Pyridinium salts—versatile reagents for the regioselective synthesis of functionalized thiazocino[2,3-b]indoles by tandem dinucleophilic reactions of thiooxindoles

The reaction of thiooxindoles with various 2- and 3-substituted pyridinium salts afforded a variety of functionalized thiazocinoindoles. The products have been prepared in good to excellent yields by regioselective dinucleophilic C/S-cyclocondensation of thiooxindoles with pyridinium salts.     

A lupane triterpenoid and other constituents of Salvia eremophila

Phytochemical investigation of the aerial parts of Salvia eremophila led to the isolation of a lupane triterpenoid, 3β, 20-dihydroxylupane-28-oic acid (1), together with eight other compounds, comprising three diterpene, two triterpene, two flavonoids and a steroidal glucoside. Their structures were elucidated by interpretation of their one-dimensional and two-dimensional NMR spectra and completed by the analysis of the HRESIMS data. Compounds 1, 2-4 and 8 were evaluated for their cytotoxicities against five human tumour cell lines. Compounds 1 and 3 hold a good potential for use in future studies due to their anti-cancer properties.     

Highly efficient synthesis of pyrimido[4,5-d]pyrimidine-2,4-dione derivatives catalyzed by iodine

A new and efficient synthesis of pyrimido[4,5-d]pyrimidine-2,4-dione derivatives through the reaction of 6-aminouracils and N,N′-bis(arylmethylidene) arylmethane in the presence of molecular iodine as a readily available and feasible catalyst.     

A versatile one-pot synthesis of 2,3,5-tri-substituted thiophenes from thiomorpholides

An efficient method for the preparation of 2,3,5-trisubstituted thiophenes in a one-pot synthesis from thiomorpholides via the thio-Claisen rearrangement was developed.     

Encapsulation of L-dopa and catechol in bovine serum albumin nanocarrier using desolvation method and their in vitro release studies

In the current study, the interaction between L-dopa and bovine serum albumin (BSA) as well as catechol and BSA is investigated separately. In order to achieve the optimum values for encapsulated efficiency (EE), the content of crosslinker/BSA, organic/aqueous phase, drug/BSA, stirring rate, and pH were closely studied taking the advantage of Taguchi method. Particle characterization was carried out using transmission electron microscopy and dynamic light scattering techniques. The most appropriate catechol and L-dopa nanoparticles in the size range of 100 nm and 65 nm, respectively, and at optimized conditions of drug/BSA = 0.1, pH = 7.4, crosslinker/BSA = 0.084, organic/aqueous phase = 4 and stirring rate 400 rpm were obtained. The most favorable EE (encapsulation efficiency) and LC (loading capacity) for L-dopa and catechol was estimated to be 88.1% and 83.6%, respectively, and the calculated LC% was achieved 93.4% and 89.7% for L-dopa and catechol, respectively. The chromatographic analyses results were also found to be in a good agreement with the obtained data for the calculated EE% and LC% values. in vitro release of loaded drugs from nanoparticles in phosphate-buffered saline (pH = 7.4, incubated at 37 ± 0.5°C under stirring rate of 100 rpm) showed the release of 78% catechol and 89% L-dopa during 480 min and 510 min, respectively.     

Water Promoted Michael Addition of Secondary Amines to α, β-Unsaturated Carbonyl Compounds Under Microwave Irradiation

A rapid Michael addition of secondary amines to α, β-unsaturated carbonyl compounds has been achieved in good to excellent yields in the presence of water under microwave irradiation. In the absence of water and under conventional method the reaction does not proceed or take place in very low yield after a long reaction time.     

Regioselective Bromination of Aromatic Amines and Phenols Using N-Benzyl-DABCO Tribromide

N-Benzyl-DABCO tribromide, a stable, solid organic ammonium tribromide, has been used as a bromine source for the regioselective and high-yielding bromination of aromatic amines and phenols. Mono-bromination proceeds well in the presence of a stoichiometric amount of bromine source at room temperature.     

Facile and Efficient One‐Pot Protocol for the Synthesis of Benzoxazole and Benzothiazole Derivatives using Molecular Iodine as Catalyst

Rapid and efficient condensation reactions of 2‐aminothiophenol and 2‐aminophenol with various aldehydes were carried out using I₂ in solvent‐free conditions with or without microwave irradiation to afford the corresponding 2‐substituted benzothiazole and benzoxazole derivatives in good to excellent yields.     

N‐Benzyl‐DABCO‐tribromide as an efficient and mild reagent for deprotection of dithioacetals

N‐Benzyl‐DABCO‐ammonium tribromide was found to be an efficient and recyclable reagent for the deprotection of dithioacetals in dichloromethane/methanol at room temperature. The reaction can be performed cleanly, in short time, and in high yield.