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A new polymorph belonging to the tetrahydropyrimidinium class of compounds, namely 6-(4-chlorophenyl)-5-(methoxycarbonyl)-4-methyl-2-(3-(trifluoromethylthio)phenylamino)-3,6-dihydropyrimidin-1-ium chloride, and a hydrate of 2-(3-bromophenylamino)-6-(4-chlorophenyl)-5-(methoxycarbonyl)-4-methyl-3,6-dihydropyrimidin-1-ium chloride, have been isolated and characterized using single-crystal X-ray diffraction (XRD). A detailed comprehensive analysis of the crystal packing in terms of the associated intermolecular interactions and a quantification of their interaction energies have been performed for both forms of the two different organic salts ( A and B) using X-ray crystallography and computational methods such as density functional theory (DFT) quantum mechanical calculations, PIXEL lattice-energy calculations (with decomposition of total lattice energy into the Coulombic, polarization, dispersion and repulsion contribution), the calculation of the Madelung constant (the EUGEN method), Hirshfeld and two-dimensional fingerprint plots. The presence of ionic [N-H]+...Cl− and [C-H]+...Cl− hydrogen bonds mainly stabilizes the crystal packing in both forms A and B, while in the case of B·H2O [N-H]+...Owater and Owater-H...Cl− hydrogen bonds along with [N-H]+...Cl− and [C-H]+...Cl− provide stability to the crystal packing. The lattice-energy calculations from both PIXEL and EUGEN methods revealed that in the case of A, form (I) (monoclinic) is more stable whereas for B it is the anhydrous form that is more stable. The analysis of the `Madelung mode' of crystal packing of two forms of A and B and its hydrates suggest that differences exist in the position of the charged ions/atoms in the organic solid state. The R/ E (distance-energy) plots for all the crystal structures show that the molecular pairs in their crystal packing are connected with either highly stabilizing (due to the presence of organic R+ and Cl −) or highly destabilizing Coulombic contacts. The difference in crystal packing and associated intermolecular interactions between polymorphs (in the case of A) or the hydrates (in the case of B) have been clearly elucidated by the analysis of Hirshfeld surfaces and two-dimensional fingerprint plots. The relative contributions of the various interactions to the Hirshfeld surface for the cationic (dihydropyrimidinium) part and anionic (chloride ion) part for the two forms of A and B and its hydrate were observed to be different. [ABSTRACT FROM AUTHOR]

Coumarin (2H-1-benzopyran-2-one) is a plant-derived natural product known for its pharmacological properties such as anti-inflammatory, anticoagulant, antibacterial, antifungal, antiviral, anticancer, antihypertensive, antitubercular, anticonvulsant, antiadipogenic, antihyperglycemic, antioxidant, and neuroprotective properties. Dietary exposure to benzopyrones is significant as these compounds are found in vegetables, fruits, seeds, nuts, coffee, tea, and wine. In view of the established low toxicity, relative cheapness, presence in the diet, and occurrence in various herbal remedies of coumarins, it appears prudent to evaluate their properties and applications further. [ABSTRACT FROM AUTHOR]

The supramolecular structures of eight aryl protected ethyl-6-methyl-4-phenyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates have been analyzed to determine the role of different functional groups on the molecular geometry, conformational characteristics and the packing of these molecules in the crystal lattice. Out of these the parafluoro substituted compound on the aryl ring exhibits conformational polymorphism, due to the different conformation of the ester moiety. This behaviour has been characterized using both powder and single-crystal X-ray diffraction, optical microscopy and differential scanning calorimetry performed on both these polymorphs. The compounds pack viathe cooperative interplay of strong N–HOC intermolecular dimers and chains forming a sheet like structure. In addition, weak C–HOC and C–Hπ interactions impart additional stability to the crystal packing. [ABSTRACT FROM AUTHOR]

The crystal structure determination of the anhydrous form of any organic compound has been a challenge because of solvent incorporation during crystallization. A device to grow anhydrous forms of low melting organic solids based on vaporization and condensation by a gradient cooling technique has been designed. Its utility has been evaluated by growing anhydrous forms of ciprofloxacin, midazolam, and ofloxacin. Ciprofloxacin crystallizes in triclinic P1̅, midazolam in monoclinic P21/n, and ofloxacin in the C2/c space group. Comparative studies on the conformational features with solvated structure show no significant variation in the aromatic moieties. A device to grow low melting organic solids in their anhydrous form has been developed and used to grow single crystals of ciprofloxacin, midazolam, and ofloxacin. [ABSTRACT FROM AUTHOR]

A fast and highly efficient method for the synthesis of some of the schiff bases of aminothiazolylbromocoumarin (4a-m) has been performed by microwave irradiation of 2'-amino-4'-(6-bromo-3-coumarinyl) thiazole (3) and substituted aromatic aldehydes (a-m). Microwave assisted reactions have resulted in better yields of the desired products than when prepared under conventional conditions. The resulting products were evaluated for their qualitative and quantitative antibacterial activity. [ABSTRACT FROM AUTHOR]

In the title compound, C11H5Br3O3, the coumarin group is planar [maximum deviation from the mean plane is 0.032 (3) Å] and makes a dihedral angle of 19.9 (3)° with the dibromoacetyl group. The crystal structure is stabilized by C—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title compound, C14H10O4S2·0.5CH3OH, the molecule adopts a gauche conformation around the central C—C bond. Intermolecular O—H...O hydrogen bonds between carboxyl groups link the molecules into zigzag chains. Between chains, the thiophene rings form π–π stacking interactions with a centroid–centroid distance of 3.98 Å. The methanol solvent molecule forms an O—H...O hydrogen bond to one carboxyl group and is disordered about a crystallographic centre of inversion. [ABSTRACT FROM AUTHOR]

The molecular structure of the title compound, C11H6Br2O3, contains a planar coumarin ring system which makes a dihedral angle of 18.5 (1)° with the bromoacetyl group. The structure is stabilized by intermolecular C—H...O hydrogen bonds and π–π aromatic stacking interactions, with centroid–centroid distances of 3.567 (2) (symmetry code: − x, − y, − z) and 3.642 (2) Å (− x + 1, − y, − z). A short Br...Br [3.4605 (8) Å] contact also stabilizes the crystal structure. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, C25H24SN4O2, the pyrrole ring adopts an envelope conformation. Each of the 4-methylbenzylidene units is planar and they make angles of 12.26 (8) and 85.46 (10)° with the four coplanar atoms of the pyrrole ring. The thiophene ring makes an angle of 75.06 (9)° with this plane. The crystal structure is stabilized by intermolecular N—H...O and C—H...O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the original report by Chopra, Venugopala, Jayashree & Guru Row [ ], the chemical name is given incorrectly in the title. The correct title is `6-Bromo-3-[2-(2-methylanilino)-1,3-thia­zol-4-yl]-2 H-chromen-2-one'. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, C19H13BrN2O2S, contains two mol­ecules ( A and B) in the asymmetric unit. The planar coumarin systems make dihedral angles of 5.47 (1) and 6.42 (1)° with the thia­zole rings in the two unique mol­ecules. The structure is stabilized by inter­molecular N—H⋯N, N—H⋯O, C—H⋯O and C—H⋯π hydrogen bonds and aromatic stacking inter­actions; intra­molecular C—H⋯O hydrogen bonds also influence the mol­ecular conformation. [ABSTRACT FROM AUTHOR]