Diethyl Derivatives Research Articles

Dialkylcyclopentadienyl derivatives of group IIIb elements; preparation and vibration spectral analysis

The preparation of dialkyl-aluminium, -gallium, and -indium cyclopentadienyls, R 2MCp, is described. For the diethyl derivatives, a detailed analysis of the IR and Raman spectra in both solid and liquid phase clearly rules out a σ-bonded structure. pentahapto ( h 5) Cyclopentadiene—metal bonding can be established for the diethylalumiuium cyclopentadienyl ether adduct; for the uncomplexed compounds, spectral evidence points towards h 2/ h 3 bonding.

The N-alkylation of some barbiturates and other acidic drugs

The synthesis of a number of new N,N'-dialkyl barbituric acids is reported. The compounds are ethyl hexobarbital, the diethyl derivatives of secobarbital and cyclobarbital, the chloroethyl derivatives ofmephobarbital and hexobarbital, and the bis(chloroethy1) derivatives of barbital, cyclobarbital, secobarbital, butobarbital and secbutobarbital.In addition, several new N-alkylated derivatives of some common anticonvulsant drugs are included. These are ethyl glutethimide, the chloroethyl derivatives of ethosuximide, glutethimide, peganone, mephenytoin and diphenylhydantoin. Infrared, N.M.R., mass spectral and gas chromatographic retention data are given.

The synthesis of volatile barbituric acid derivatives

The synthesis of several new N,N?-dialkyl barbituric acids is reported. The compounds are the diethyl derivatives of pentobarbital and amobarbital, and the bis(chloroethyl) derivatives of pentobarbital, amobarbital and phenobarbital. Separation and isolation of mono- and di-methyl, mono- and diethyl derivatives of the three barbituric acids are also described. Infrared, mass and N.M.R. spectral data are given.��� Of the derivatives, only the methylated compounds are significantly more volatile than the parent acids.

Protonation of fumaric and maleic acids and their diethyl derivatives

Protonation of fumaric and maleic acids and their diethyl derivatives

Reductive C-alkylation. II

Methylpyrrole carboxylic esters generally are reductively methylated at 25–45°. Some are also reductively alkylated by aliphatic aldehydes generally to give, for example, 2,3(or 2,4)-dimethyl-4(or 3)-alkyl-5-carbethoxypyrroles, using hydriodic acid or HCl/AcOH–Zn/Hg respectively. An analogous alkylation by glyoxylic acid gave 5-carbethoxyhemopyrrole-dicarboxylic ester. Using HI, paraldehyde at 100° gave diethyl derivatives of dimethylpyrroles, and aminoacetal at 35° converted 2,4-dimethyl-3-acetylpyrrole into its 5-(2-amino-ethyl)-derivative. Reductive alkylations have been most useful with pyrroles but HI converted 2-biphenylcarbaldehyde into fluorene.

Effect of the Basic Strength of Attached Groups on Light Absorption Spectra I. Light Absorption of Triphenylmethane Dyes

The electronic energy levels of typical triphenylmethane dyes, Dobner's Violet and Rosaniline, are calculated through the simple LCAO MO method. The electron densities and the bond orders in the ground states are also computed. Then, with these values of electron densities and the bond orders, the differences of the coulomb and of the resonance integrals, Δ α i and Δ β i j , respectively, as well as those between the carbon and the nitrogen atoms are taken into account and the electronic energy levels calculated above are modified by perturbation method. The differences of the coulomb integrals between the carbon and the nitrogen atoms cause profound effects to the absorption energy which amount to 23∼27 Kcal (40∼50 %), whereas those of different carbon atoms affect to the absorption only 4 Kcal (10 %). The energy levels of the various derivatives of Dobner's Violet and Rosaniline, e.g. dimethyl and diethyl derivatives of Dobner's Violet, Malachite Green, Brilliant Green, Hoffmann's Violet. Crystal Violet...