High-performance liquid chromatographic methods were developed for the isolation and quantitative determination of the group B soyasaponins, including 2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP)-conjugated soyasaponins alphag, betag, and betaa, and their non-DDMP counterparts, soyasaponins V, I, and II, respectively, with formononetin used as the internal standard. The limits of qu...

new macrocyclic polyether-diester ligands (3-5) containing the 4h-pyran-4-one subcyclic unit have been prepared by treating various glycols with dimethyl chelidonate (10). in the reaction of compound 10 with ethylene glycol and diethylene glycol, two noncyclic diester and tetraester (6-9) were produced in each case. the new marcocyclic ligand 4 formed stable complexes with benzylammonium perchl...

Wells–Dawson tungsten heteropolyacid (H6P2W18O62) has been applied as an effective heterogeneous catalyst for one-pot synthesis of spiro[4H-pyran-3,3’-oxindoles] via reaction of various isatins, malonitrile and 1,3-dicarbonyl compound in water. The corresponding products were obtained in high yields. The catalysts were easily recycled and reused without loss of their catalytic activity. 

Egg shell has been utilized as a natural, green, reusable and eco-friendly reagent for the synthesis of spiro[4H-pyran-oxindole] derivatives by one-pot multicomponent reaction of isatins, 1,3-diketones, and malononitrile/ ethyl cyanoacetate. Good functional group tolerance and broad scope of usable substrates are other prominent features of the present methodology.

In the title compound, C15H18N2O2S, the 2,3-di-hydro-1-benzo-thio-pyran ring adopts a sofa conformation and the hydantoin ring is twisted with respect to the benzene ring at 78.73 (17)°. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into inversion dimers.

Introduction: Due to the cell labeling potentials of various metal-maltol complexes, the idea of developing a possible cell labeling imaging agent using single photon emission computed chromatography (SPECT) with[111In]-maltolate complex has been investigated. Methods: [111In] labeled 3-hydroxy-2-methyl-4H-pyran-4-onate ([111In]-maltolate) was prepared using f...

Infections are one of the most important causes of death, disability and inappropriate conditions for millions of people around the world. Therefore, the development in prognosis, prevention and treatment of infectious diseases made a considerable progress in designing and synthesis of new antimicrobial drugs. Nowadays, due to the increase in microbial resistance, discovery of new compounds wit...

In this work 3-chloro-2-chlorocarbonylbenzo[b]thiophene (1) was prepared from cinnamic acid and then converted into the acid hydrazide 2. The azomethines 3a-e were prepared from the corresponding aryl aldehydes and the acid hydrazide 2. Treatment of compound 2 with formic acid gave the N-formyl acid hydrazide 4, which upon refluxing with phosphorous pentoxide or phosphorous pentasulphide in xyl...

Abstract To find novel classes of potential fuel additives multivalent activity, particularly antioxidants, a series recently synthesized ethyl-6-amino-5-cyan-methyl-4-aryl-4H-pyran-3-carboxylates have been investigated using model oxidative reactions. The compounds studied appear to be prospective inhibitors hydrocarbons oxidation. Some them are antioxidants combined action, breaking the chain...