TRYPTAMINES, CARBOLINES, AND RELATED COMPOUNDS: PART VII. INTERNUCLEAR CYCLIZATION ONTO A PYRIDINE RING

1960 ◽  
Vol 38 (11) ◽  
pp. 2273-2276 ◽  
Author(s):  
R. A. Abramovitch
Keyword(s):  
Pyridine Ring ◽  
Related Compounds

not available

Synthesis and Ring Cyclization - Expansion - Contraction Reactions of Some New 2,2-Disubstituted Indan-1,3-diones and Related Compounds

2006 ◽  
Vol 59 (1) ◽  
pp. 59 ◽  
Author(s):  
Craig J. Roxburgh ◽  
Lee Banting
Keyword(s):  
Catalytic Hydrogenation ◽  
Pyridine Ring ◽  
Functional Group ◽  
Chemical Properties ◽  
Ring Expansion ◽  
Ring Structure ◽  
Side Reactions ◽  
The Third ◽  
Ring Expansion Reaction ◽  
Related Compounds

We have found that the hydrochloride of 2-phenyl-2-[2-(2-piperidyl)ethyl]-4,5,6,7-tetrahydroindan-1,3-dione 1 possesses marked analgesic activity (100% inhibition referenced to codeine) and report, as part of an extensive synthetic program, the synthesis of 38 new and structurally related compounds. Selective catalytic hydrogenation of the pyridine ring of 2-phenyl-2-[2-(2-pyridyl)ethyl]-indan-1,3-dione 2 yields the nine-membered nitrogen-containing heterocycle 6 by a novel ring cyclization–expansion reaction. The structural and functional group parameters required for this novel ring-expansion reaction have been extensively and thoroughly investigated through the synthesis of a series of structurally related compounds; principally by modification, substitution, and replacement of the various functionality contained within 2. In addition, we report the synthesis of a series of new 2-methyl-2-(ω-N-phthalimidoalkyl)-indan-1,3-diones 41, 45, and 53, two of which, like the parent 2-phenyl substituted indan-1,3-dione 2, also undergo a novel ring cyclization–expansion reaction to yield eight- and nine-membered nitrogen-containing rings. However, in these cases, further transannular reactions occur to produce the new 5,5- and 5,6-ring-fused nitrogen-containing heterocycles 44, 48 and 51, 52. Hydrazinolysis of the third, 2-methyl-2-(4-N-phthalimidobutyl)-indan-1,3-dione yields the new azepine-containing ring structure 56 by direct cyclization. Furthermore, some interesting and unexpected chemical properties of the final compounds, which include selective and non-selective pyridine-ring hydrogenations and a few unexpected side reactions, are described.

scholarly journals Three closely related 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridines: synthesis, molecular conformations and hydrogen bonding in zero, one and two dimensions

2017 ◽  
Vol 73 (3) ◽  
pp. 298-304
Author(s):  
Belakavadi K. Sagar ◽  
Kachigere B. Harsha ◽  
Hemmige S. Yathirajan ◽  
Kanchugarakoppal S. Rangappa ◽  
Ravindranath S. Rathore ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Pyridine Ring ◽  
Chair Conformation ◽  
Two Dimensions ◽  
Relative Orientation ◽  
Molecular Conformations ◽  
Space Groups ◽  
Related Compounds ◽  
Trifluoromethyl Groups ◽  
Centrosymmetric Dimers

In each of 1-(4-fluorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C21H19F4N3O2S, (I), 1-(4-chlorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C21H19ClF3N3O2S, (II), and 1-(3-methylphenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C22H22F3N3O2S, (III), the reduced pyridine ring adopts a half-chair conformation with the methylsulfonyl substituent occupying an equatorial site. Although compounds (I) and (II) are not isostructural, having the space groups Pbca and P212121, respectively, their molecular conformations are very similar, but the conformation of compound (III) differs from those of (I) and (II) in the relative orientation of the N-benzyl and methylsulfonyl substituents. In compounds (II) and (III), but not in (I), the trifluoromethyl groups are disordered over two sets of atomic sites. Molecules of (I) are linked into centrosymmetric dimers by C—H...π(arene) hydrogen bonds, molecules of (II) are linked by two C—H...O hydrogen bonds to form ribbons of R 3 3(18) rings, which are themselves further linked by a C—Cl...π(arene) interaction, and a combination of C—H...O and C—H...π(arene) hydrogen bonds links the molecules of (III) into sheets. Comparisons are made with the structures of some related compounds.

scholarly journals Crystal structure of (15,20-bis(2,3,4,5,6-pentafluorophenyl)-5,10-{(4-methylpyridine-3,5-diyl)bis[(sulfanediylmethylene)[1,1′-biphenyl]-4′,2-diyl]}porphyrinato)nickel(II) dichloromethane x-solvate (x > 1/2)

2019 ◽  
Vol 75 (10) ◽  
pp. 1558-1563
Author(s):  
Florian Gutzeit ◽  
Tjorge Neumann ◽  
Christian Näther ◽  
Rainer Herges
Keyword(s):  
Crystal Structure ◽  
Pyridine Ring ◽  
Structural Model ◽  
Coordination Geometry ◽  
Pyridine Nitrogen Atom ◽  
Apical Position ◽  
Acta Cryst ◽  
Pyridine Nitrogen ◽  
Related Compounds ◽  
Porphyrin Moiety

The title compound, [Ni(C64H33F10N5S2)]·xCH2Cl2, consists of discrete NiII porphyrin complexes, in which the five-coordinate NiII cations are in a distorted square-pyramidal coordination geometry. The four porphyrin nitrogen atoms are located in the basal plane of the pyramid, whereas the pyridine N atom is in the apical position. The porphyrin plane is strongly distorted and the NiII cation is located above this plane by 0.241 (3) Å and shifted in the direction of the coordinating pyridine nitrogen atom. The pyridine ring is not perpendicular to the N4 plane of the porphyrin moiety, as observed for related compounds. In the crystal, the complexes are linked via weak C—H...F hydrogen bonds into zigzag chains propagating in the [001] direction. Within this arrangement cavities are formed, in which highly disordered dichloromethane solvate molecules are located. No reasonable structural model could be found to describe this disorder and therefore the contribution of the solvent to the electron density was removed using the SQUEEZE option in PLATON [Spek (2015). Acta Cryst. C71, 9–18].

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