Ramalingam Murugan

Synthesis and in vivo antidiabetic activity of novel dispiropyrrolidines through [3+2] cycloaddition reactions with thiazolidinedione and rhodanine derivatives.

The synthesis of a series of novel dispiropyrrolidines has been accomplished by 1,3-dipolar cycloaddition reaction with 5-arylidene-1,3-thiazolidine-2,4-dione and 5-arylidene-4-thioxo-1,3-thiazolidine-2-one derivatives as dipolarophiles. The structure and stereochemistry of the cycloadduct have been established by single crystal X-ray structure and spectroscopic techniques. Molecular docking studies were performed on 1FM9 protein. The synthesized compounds were screened for their antidiabetic activity on male Wistar rats.

Synthesis of Novel Spiroheterocycles Through 1,3-Dipolar Cycloaddition of Azomethine Ylides with Triarylideneacetylacetone Through Decarboxylation

Triarylideneacetylacetone undergoes regioselective 1,3-dipolar cycloaddition reactions with azomethine ylide derived from isatin and L-proline/sarcosine/octahydro-1H-indole-2-carboxylic acid by decarboxylation, affording a series of spiroheterocycles. This one-pot, three-component tandem reaction is efficient and yields novel spiroheterocylic compounds in good yields. The structure and stereochemistry of the cycloadduct have been established by single-crystal x-ray and spectroscopic techniques.

(E)-3-Hydr­oxy-13-methyl-16-[4-(methyl­sulfan­yl)benzyl­idene]-7,8,9,11,12,13,15,16-octa­hydro-6H-cyclo­penta­[a]phen­an­­­­thren-17(14H)-one

In the title compound, C26H28O2S, the dihedral angles between the mean plane of the five membered ring and the 4-(methylsulfanyl)benzylidine ring in the two crystallographically independent molecules are 34.05 (10) and 40.53 (15)°. The packing is stabilized by intermolecular O—H⋯O and C—H⋯O interactions.

(1E,4E)-1,5-Bis(2-chlorophenyl)penta-1,4-dien-3-one

The title compound, C17H12Cl2O, crystallizes in a centrosymmetric space group. The dihedral angle between the two benzene rings is 24.7 (1)°. The crystal packing is characterized by non-classical C—H...O and C—H...Cl inter- and intramolecular hydrogen bonds.

Synthesis of Highly Substituted Pyrrolidines Through 1,3-Dipolar Cycloaddition Reaction of N-Metalated Azomethine Ylides with Triarylideneacetylacetone as Dipolarophile Using Titanocene Dichloride

Abstract The 1,3-dipolar cycloaddition reaction of tryarylideneacetyacetone derivatives with N-metalated azomethine ylides in the presence of titanocene dichloride and triethylamine has been investigated. This two-step synthetic sequence is very efficient and yielded the highly substituted pyrrolidines in good yields. The structure and stereochemistry of one of the products has been established by single-crystal x-ray structure and spectroscopic techniques.

1-[2-Oxo-1'-phenyl-2',3',5',6',7',7a'-hexa-hydroindoline-3-spiro-3'-1'H-pyrrolizin-2'-yl]-3-phenyl-prop-2-en-1-one.

In the title compound, C29H26N2O2, one of the pyrrolidine rings in the pyrrolizine system is disordered, with site occupancies of ca 0.55 and 0.45. Both components of the disordered pyrrolidine ring adopt envelope conformations, whereas the other pyrrolidine ring adopts a twist conformation. The molecules are linked into centrosymmetric dimers by N—H⋯O hydrogen bonds and the dimers are connected via C—H⋯π interactions.

3-(4-Fluoro­phenyl)-1-[1′-(4-fluoro­phenyl)-2-oxo-5′,6′,7′,7a′-tetra­hydro-1H-indole-3(2H)-spiro-3′(2′H)-1H′-pyrrol­izin-2′-yl]prop-2-en-1-one

In the title compound, C29H24F2N2O2, one of the pyrrolidine rings of the pyrrolizine system is disordered over two sites, with occupancy factors 0.734:0.266 (12). Both components of the disordered pyrrolidine ring adopt envelope conformations, whereas the other pyrrolidine ring adopts a twist conformation. The molecules are linked into centrosymmetric dimers by N—H⋯O hydrogen bonds and the dimers are connected via C—H⋯π interactions. The crystal structure is also stabilized by intermolecular C—H⋯F hydrogen bonds.

9-Ethyl-2,3-dihydro-9H-carbazol-4(1H)-one.

In the title compound, C28H30N2O2, the cyclohexene ring system adopts a sofa conformation. The crystal structure is stabilized by C—H⋯O interactions between methyl H atoms of the ethyl substituents and the O atoms of carbonyl groups of adjacent molecules, and by an intermolecular carbonyl–carbonyl interactions [3.207 (2) Å]

(E,E)-1,5-Di-2-thienylpenta-1,4-dien-3-one.

In the title compound, C13H10OS2, the dihedral angle between the thiophene rings is 14.3 (1)°. The molecular structure is stabilized by C—H⋯π interactions between a thiophene H atom and an adjacent thiophene ring, and by intermolecular C—H⋯O hydrogen bonds.

(1′S)-4-(3,4-Dichlorophenyl)-1′-(3,5-dimethoxyphenyl)-1,2,3,4-tetrahydronaphthalene-2-spiro-2′-pyrrolizidine-3′-spiro-3′′-indoline-1,2′′-dione

In the title compound C37H32Cl2N2O4, the unsubstituted pyrrolidine ring shows a twist conformation whereas the substituted pyrrolidine ring shows an envelope conformation. The dimethoxy benzene ring is perpendicular to the tetralone ring, making a dihedral angle of 89.94 (5)°. Molecules are linked into centrosymmetric dimers by N—H⋯O hydrogen bonds and the crystal structure is stabilized by C—H⋯π interactions and C—H⋯O hydrogen bonds. One methoxy group is disordered over two positions with the site occupancy factors of 0.84 (2) and 0.16 (2).