3-Phenyl-5-isothiazole carboxamides with potent mGluR1 antagonist activity

Dual roles of bisphosphines and epoxides: Rh-catalyzed highly chemoselective and diastereoselective (3 + 2) transannulations of 1,2,3-thiadiazoles with cyanoepoxides

Dual roles of bisphosphines and epoxides are demonstrated in highly chemoselective and diastereoselective (3 + 2) transannulations.

Polymorphism of methyl 4-amino-3-phenylisothiazole-5-carboxylate: an experimental and theoretical study

Being a close analogue of amflutizole, methyl 4-amino-3-phenylisothiazole-5-carboxylate (C₁₁H₁₀N₂O₂S) was assumed to be capable of forming polymorphic structures. Noncentrosymmetric and centrosymmetric polymorphs have been obtained by crystallization from a series of more volatile solvents and from denser tetrachloromethane, respectively. Identical conformations of the molecule are found in both structures. The two polymorphs differ mainly in the intermolecular interactions formed by the amino group and in the type of stacking interactions between the π-systems. The most effective method for revealing packing motifs in structures with intermolecular interactions of different types (hydrogen bonding, stacking, dispersion, etc.) is to study the pairwise interaction energies using quantum chemical calculations. Molecules form a column as the primary basic structural motif due to stacking interactions in both polymorphic structures under study. The character of a column (straight or zigzag) is determined by the orientations of the stacked molecules (in a `head-to-head' or `head-to-tail' manner). Columns bound by intermolecular N-H...O and N-H...N hydrogen bonds form a double column as the main structural motif in the noncentrosymmetric structure. Double columns in the noncentrosymmetric structure and columns in the centrosymmetric structure interact strongly within the ab crystallographic plane, forming a layer as a secondary basic structural motif. The noncentrosymmetric structure has a lower density and a lower (by 0.59 kJ mol^-1) lattice energy, calculated using periodic calculations, compared to the centrosymmetric structure.

Synthesis of Isoselenazoles and Isothiazoles from Demethoxylative Cycloaddition of Alkynyl Oxime Ethers

A general method for the synthesis of isoselenazoles and isothiazoles has been developed by the base-promoted demethoxylative cycloaddition of alkynyl oxime ethers using the cheap and inactive Se powder and Na₂S as selenium and sulfur sources. This transformation features the direct construction of N-, Se-, and S-containing heterocycles through the formation of N-Se/S and C-Se/S bonds in one-pot reactions with excellent functional group tolerance.

Access to 4-substituted isothiazoles through three-component cascade annulation and their application in C–H activation

The use of EtOCS₂k enabled the annulation of isopropene derivatives with NH₄I, affording various 4-substituted isothiazoles in good yields.

Virtual Screening and Molecular Dynamics Study of Potential Negative Allosteric Modulators of mGluR1 from Chinese Herbs

The metabotropic glutamate subtype 1 (mGluR1), a member of the metabotropic glutamate receptors, is a therapeutic target for neurological disorders. However, due to the lower subtype selectivity of mGluR1 orthosteric compounds, a new targeted strategy, known as allosteric modulators research, is needed for the treatment of mGluR1-related diseases. Recently, the structure of the seven-transmembrane domain (7TMD) of mGluR1 has been solved, which reveals the binding site of allosteric modulators and provides an opportunity for future subtype-selectivity drug design. In this study, a series of computer-aided drug design methods were utilized to discover potential mGluR1 negative allosteric modulators (NAMs). Pharmacophore models were constructed based on three different structure types of mGluR1 NAMs. After validation using the built-in parameters and test set, the optimal pharmacophore model of each structure type was selected and utilized as a query to screen the Traditional Chinese Medicine Database (TCMD). Then, three different hit lists of compounds were obtained. Molecular docking was used based on the latest crystal structure of mGluR1-7TMD to further filter these hits. As a compound with high QFIT and LibDock Score was preferred, a total of 30 compounds were retained. MD simulation was utilized to confirm the stability of potential compounds binding. From the computational results, thesinine-4'-O-β-d-glucoside, nigrolineaxanthone-P and nodakenin might exhibit negative allosteric moderating effects on mGluR1. This paper indicates the applicability of molecular simulation technologies for discovering potential natural mGluR1 NAMs from Chinese herbs.

Ring transformation of (4-chloro-5H-1,2,3-dithiazol-5-ylidene)acetonitriles to 3-haloisothiazole-5-carbonitriles

Improved conditions for the ring transformation of 1,2,3-dithiazoles into isothiazole-5-carbonitriles are presented together with mechanistic rationale.