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3. ChemInform Abstract: 1,3-Dihydro-2H-imidazo(4,5-b)quinolin-2-ones. Inhibitors of Blood Platelet cAMP Phosphodiesterase and Induced Aggregation

Author

E. Gillespie, H. R. Roth, J. S. Fleming, Wright John J, D. L. Wedding, E. C. R. Smith, and Nicholas A. Meanwell

Subjects
Hydrolysis, Biochemistry, Chemistry, Alkoxy group, medicine, Phosphodiesterase, Platelet, General Medicine, Methylation, Thrombus, medicine.disease, Inhibitory postsynaptic potential, In vitro
Abstract

A series of 1,3-dihydro-2H-imidazo[4,5-b]quinolin-2-one derivatives was synthesized and evaluated as inhibitors of cAMP hydrolysis by a crude human platelet phosphodiesterase preparation and as inhibitors of ADP- and collagen-induced aggregation of rabbit blood platelets. The parent structure 7a, demonstrated potent inhibitory activity that was enhanced by the introduction of alkyl, alkoxy, or halogen substituents at the 5-, 6-, 7-, and 8-positions. Methylation at N-1 or N-3 produced weaker inhibitors of cAMP PDE and platelet aggregation. 1,3,9,9a-Tetrahydro-2H-imidazo[4,5-b]quinolin-2-ones (6) were found to be equipotent with their fully oxidized congeners (7). On the basis of platelet inhibitory properties in vitro, efficacy at preventing thrombus formation in animal models of thrombosis, and a favorable hemodynamic profile, 1,3-dihydro-7,8-dimethyl-2H- imidazo[4,5-b]quinolin-2-one (7o, BMY 20844) was selected for advancement into toxicological evaluation and clinical trial. An efficient synthesis of 7o is described.

Published
2010
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6. ChemInform Abstract: Resonance Energy Calculation; the MM2ERW Force Field

Author

H.‐W. Lennartz, R. Breuckmann, Wolfgang R. Roth, Oliver Adamczak, and Roland Boese

Subjects
Delocalized electron, Chemistry, Quantum mechanics, Nanotechnology, General Medicine, Conjugated system, Force field (chemistry)
Abstract

The additivity of the thermochem. conjugation energy in acyclic systems allows one to extend force-field calcns. to conjugated p systems without embarking on quantum-mech. methods. The approach fails with cyclic delocalized systems, where resonance effects become important. Here the method provides the ref. value needed to calc. resonance energies.

Published
2010
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9. ChemInform Abstract: The Benzene Ring as Dienophile in an Intramolecular (4 + 2) Cycloaddition: Degenerate Rearrangement of 7,8-Benzobicyclo(4.2.2)deca- 2,4,7,9-tetraene

Author

Wolfram Grimme, Rolf Breuckmann, Wolfgang R. Roth, and Thomas Grommes

Subjects
chemistry.chemical_classification, chemistry.chemical_compound, Chemistry, Intramolecular force, Degenerate energy levels, General Medicine, Bridged compounds, Ring (chemistry), Benzene, Medicinal chemistry, Cycloaddition, Deca
Published
2010
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16. ChemInform Abstract: Bicyclo(4.4.0)deca-1,6-diene-2,7-diyl: A 1,4-Didehydrobutadiene Derivative

Author

Rolf Gleiter, T. Wasser, Hagen Weigl, and Wolfgang R. Roth

Subjects
chemistry.chemical_compound, Standard enthalpy of reaction, Diene, chemistry, Hydrogen, Diradical, Enthalpy, Physical chemistry, chemistry.chemical_element, General Medicine, Supercritical fluid, Derivative (chemistry), Standard enthalpy of formation
Abstract

From the NO- and O2-dependence of the trapping rate of 1,6-cyclodecadiyne (3) in the gas phase and in supercritical CO2 in the temperature range 160–290°C, the enthalpy profile for the equilibrium 3 ⇌ 4 has been established. For the diradical 4, a heat of formation of 116.2 kcal · mol−1 is obtained, which agrees well with the expectation value derived by the abstraction of two hydrogen atoms from hexahydronaphthalene (5).

Published
2010
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19. ChemInform Abstract: Norbornanes. Part 21. Bridging Strain in Norbornyl and Oxanorbornyl Cations

Author

Cyril A. Grob, Wolfgang R. Roth, Hans‐Werner Lennartz, Guang Yi Wang, and Peter Flury

Subjects
chemistry.chemical_classification, Crystallography, Bridging (networking), Strain (chemistry), Chemistry, General Medicine, Bridged compounds, 2-Norbornyl cation
Abstract

Further evidence is presented that the 2-norbornyl cation is stabilized primarily by C(2)-C(6) bridging, and that C(2)-C(7) bridging leads to prohibitive strain.

Published
1988
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