50 research outputs found
A Highly Efficient Method for Synthesis of Bisarylmethylidenes of Cyclic Ketones in [BMIm]Cl/NaOH System as New and Recyclable Catalyst
An ionic liquid 1-Butyl-3-methylimidazoliumchloride[BMIm]Cl/sodium hydroxide system, was employed as a catalyst for the fast and one-pot crossed aldol-condensation of various aromatic aldehydes and cyclic ketones, to produce a variety of substituted α,α'-bis(benzylidene)-cycloalkanones under neat conditions. This process is simple, efficient and environmentally benign and proceeds in high yield and short reaction times. The ionic liquid can be recycled for subsequent reactions without any appreciable loss of efficiency
rac-3-[(Anilino)(naphthalen-2-yl)methyl]thian-4-one
In the title compound, C22H21NOS, the thiopyranone ring adopts a chair-like conformation with the substituent in the axial position. The relative configuration of the racemic compound is 3R,7S according to the numbering scheme used in this publication. In the crystal packing, centrosymmetric dimers are built up via N—H⋯O hydrogen bonds, with graph set R
2
2(8)
rac-3-[(3-Chloroanilino)(4-chlorophenyl)methyl]thian-4-one
In the title compound, C18H17Cl2NOS, the thiopyranone ring adopts a chair conformation, with the substituent in the axial position. The dihedral angle between the two benzene rings is 89.43 (1)°. In the crystal, molecules form inversion dimers through intermolecular N—H⋯O hydrogen bonds [graph set R
2
2(8)]
(2E,6E)-2,6-Bis(4-methylbenzylidene)cyclohex-3-en-1-one
The title compound, C22H20O, shows an approximately planar cyclohexenone ring [maximum deviation = 0.069 (4) Å], with a disordered position of the C=C bond [ratio = 0.71 (2)/0.29 (2)]. The benzene rings of the 4-methylbenzylidene units, attached in the 2- and 6-positions to the cyclohexenone ring, are rotated in the same direction by 28.6 (4) and 22.4 (4)°, with respect to the mean plane of the cyclohexenone ring [fraction 0.71 (2); maximum deviation = 0.06 (3) Å]. In the crystal, molecules are packed in the manner of a distorted hexagonal rod packing with their long axes all aligned along [201]. A number of C—H⋯π interactions stablize the crystal structure
(4Z,6Z)-4,6-Bis(4-methoxybenzylidene)-2,2-dimethyl-1,3-dioxan-5-one
The title compound, C22H22O5, crystallizes with two independent molecules in the asymmetric unit, both of which possess pseudo-C
s symmetry. The central 1,3-dioxanone rings have envelope conformations, with the C atom bearing the two methyl groups at the flap. The benzene rings of the methoxybenzylidene units, attached in the 4- and 6-positions on the central 1,3-dioxanone rings, are tilted in the same direction with dihedral angles varying between 8.2 (1) and 18.1 (1)°. The crystal packing is influenced by π-stacking interactions of the parallel displaced type [centroid–centroid distance of 3.723 (1) Å for molecule 1 and 3.884 (1) Å for molecule 2, with ring slippages of 1.432 and 1.613 Å, respectively] and the T-shaped type, with the long molecular axes all aligned along [010]
A green, inexpensive and efficient organocatalyzed procedure for aqueous aldol condensations
A facile and general procedure is presented for diethylamine-catalyzed double crossed aldol condensation of cyclic ketones with various aromatic aldehydes under aqueous conditions. Excellent yields of 3,5-bisarylmethylidenes of homocyclic and heterocyclic ketones are achieved in a one-pot procedure. Furthermore, the methodology is efficiently applied to the synthesis of chalcones from their corresponding methyl ketones. In the majority of the cases studied, products precipitate from the reaction mixtures and the medium is recycled in subsequent several reactions without significant loss of activity
Correlation of Circulating Omentin-1 with Bone Mineral Density in Multiple Sclerosis: The Crosstalk between Bone and Adipose Tissue
BACKGROUND: Patients with multiple sclerosis (MS) are at increased risk of osteoporosis and fractures. Adipose tissue-derived adipokines may play important roles in the osteoimmunology of MS. In order to determine whether omentin-1 and vaspin may be related to bone health in MS patients, we compared circulating levels of these recently identified adipokines, between MS patients and healthy controls. METHODS: A total of 35 ambulatory MS patients with relapsing-remitting courses were compared with 38 age- and sex-matched healthy controls. Bone mineral density (BMD) was determined for the lumbar spine (L2-L4) and the proximal femur using dual-energy x-ray absorptiometry. Circulating omentin-1, vaspin, osteocalcin, osteopontin, osteoprotegerin, the receptor activator of nuclear factor-κB ligand, matrix metalloproteinase 9, C-reactive protein and 25-hydroxy vitamin D levels were evaluated by highly specific enzyme-linked immunosorbent assay methods. RESULTS: There was no significant difference between the two groups regarding bone-related cytokines, adipocytokines, and the BMD measurements of patients with MS and the healthy controls. However, in multiple regression analysis, serum omentin-1 levels were positively correlated with BMD at the femoral neck (β = 0.49, p = 0.016), total hip (β = 0.42, p = 0.035), osteopontin (β = 0.42, p = 0.030) and osteocalcin (β = 0.53, p = 0.004) in MS patients. No correlations were found between vaspin, biochemical, and BMD measures in both groups. CONCLUSIONS: Elevated omentin-1 serum levels are correlated with BMD at the femoral neck and the serum levels of osteocalcin and osteopontin in MS patients. Therefore, there is crosstalk between adipose tissue and bone in MS
Efficient and Rapid Solvent-Free Acetylation of Alcohols, Phenols, and Thiols Using Catalytic Amounts of Sodium Acetate Trihydrate
Under solvent-free conditions, different alcohols and phenols were efficiently acetylated at room temperature within short time periods by using acetic anhydride in the presence of catalytic quantities of sodium acetate trihydrate, which is a very inexpensive and mild reagent. Thiols were also shown to behave equally well under the same conditions. Chemoselective protection of less hindered alcohols in the presence of bulkier homologues and phenols in the presence of alcohols was achieved using competitive experiments
Microwave-assisted deoximation under solvent-free conditions using Bi(NO<sub>3</sub>)<sub>3</sub>.5H<sub>2</sub>O supported onto montmorillonite K-10<b style=""></b>
831-833Oximes are oxidatively
deprotected by bismuth nitrate supported onto montmorillonite K-10 to the
parent carbonyl compound in high yields upon exposure to microwave irradiation
in solventless system