Synge

13C Chemical shifts and resolved carbon–proton couplings of 39 deoxybenzoins and 11 acetophenones, most of which have naturally occurring substitution patterns, are assigned. Individual benzene rings turned out to have typical parameters not affected by structural variations in the rest of the molecule. Due to substitutional saturation, however, these benzenoid carbon shifts markedly deviate from increment additivity. A few trends of these deviations are described. Phenolic hydrogens, fixed between hydroxyl and carbonyl oxygen due to internal hydrogen bonding, are shown to give rise to additional carbon-splittings.

“…This is expected, as para-substitution is always involved (8). The deviation affects all ring carbons in the subsystem and ranges from 8.9ppm downfield to 5.7ppm upfield.…”

Section: Chemical Shiftsmentioning

confidence: 77%

Section: Internal Chelationmentioning

confidence: 85%

See 1 more Smart Citation

Carbon-13 nmr shifts and C—H coupling constants of deoxybenzoins and related acetophenones

Jha¹,

Zilliken²,

Offermann³

et al. 1981

“…ref. 12), but the upfield shift for the protons attached to C-6 has no precedents, as far as we are aware; a tentative explanation could lie in unfavorable dipole-dipole interactions between the C-Br and C=O bonds in this compound. Can The representative pyrazoloazepinone 8e was converted into the unstable, reactive chloro compound 14 on treatment with phosphorus oxychloride.…”

Section: ) Than Anisotropic Influencesmentioning

confidence: 78%

Synthesis, reactions, and nuclear magnetic resonance spectroscopy of 4-methyl-6H-pyrazolo(3,4-b)azepin-7-ones

Sharma¹,

Lynch²

1979

Reactions of various 5-aminopyrazoles with ethyl levulinate in acetic acid have been shown to furnish moderate to good yields of the correspondingly substituted 4-methyl-6H-pyrazolo-(3,4-b)azepin-7-ones, accompanied by the acetamidopyrazoles. The courses of methylation and of bromination reactions of some of the pyrazoloazepinones have been explored and defined, and conversion of one pyrazoloazepinone into 7-chloropyrazoloazepine and thence by nucleophilic displacements into 7-(substituted amino)pyrazoloazepines has been effected. Structural assignments, tautomeric preferences, and through-space interactions between substituents were established through nuclear magnetic resonance spectroscopy (1H and 13C). Some members of the pyrazoloazepinone series exhibit significant anti-inflammatory and analgesic effects in mice.

“…In addition, the energies of the ground state and various radical amido substituent is particularly significant in that its influence is secondarv to the other substituents. It lAlfred P. Sloan Foundation Fellow 1975-1977 Camille is also useful to determine the photoelectron spectra and Henry Dreyfus Teacher-Scholar Grant Recipient 1972-of benzamides since three of the I P values can be 1977. associated with the a~n i d e moiety and thus the inCan. J. Chem.…”

Section: Introductionmentioning

confidence: 99%

Photoelectron spectra of substituted benzamides

McAlduff¹,

Lynch²,

Houk³

1978

The photoelectron spectra of the following substituted benzamides have been determined: p-CH3O, p-CH3, p-Cl, H, p-F, p-CN, p-NO2, m-CH3O, m-CH3, m-Cl, and m-NO2. The first six ionization potentials have been assigned with reference to the phenyl and amide moieties. As an aid to the assignment CNDO/S calculations have been performed on the methoxy, methyl, and nitro benzamides. Linear relationships have been shown to exist between the first phenyl IP of disubstituted and monosubstituted benzenes. The slopes of these relationships have been shown to be related to the electron releasing ability of the substituent.By comparison of the pes data with nmr chemical shifts, the first phenyl IP has been shown to be related to the electron density at the position of substitution of the amide group. Likewise, the amide IP centered on the nitrogen has been shown to be related to the electron density on nitrogen.