354-03-0Relevant academic research and scientific papers
Synthetic routes for a variety of halogenated (chiral) acetic acids from diethyl malonate
Mazenauer, Manuel R.,Manov, Stole,Galati, Vanessa M.,Kappeler, Philipp,Stohner, Jürgen
, p. 55434 - 55440 (2018/04/05)
Chiral halomethane is the smallest stable molecule with a single asymmetric C-atom and halogenated acetic acids often serve as precursors. We focus on a synthetic route to synthesise chiral halogenated acetic acids with F, Cl, Br, and H/D isotopic substitution at the α-C-atom starting from diethyl malonate. This reactant is easily available, cheap and allows the obtainment of target acids in a few reaction steps with great versatility. Among all of the possible fully halogenated acetic acids (more than one hundred, which are, in principle, accessible by this route), there are only a small number of chiral halogenated acetic acids, which have been synthesized following the devised synthetic route.
Fermi Resonance Structure and Femtosecond Quantum Dynamics of a Chiral Molecule from the Analysis of Vibrational Overtone Spectra of CHBrClF
Beil, Andreas,Luckhaus, David,Quack, Martin
, p. 1853 - 1875 (2007/10/03)
The rovibrational spectra of bromochlorofluoromethane (CHBrClF) were measured at intermediate (0.1 cm-1) and high resolution (0.001 cm-1) between the far infrared (20 cm-1) and the visible range of the spectrum (14000 cm-1) by interferometric Fourier transform techniques and diode laser techniques in stationary samples and supersonic jets.All fundamentals and numerous combinations and overtone transitions could be assigned and their band positions and integrated strengths were determined.A quantitative interpretation of the complex multiple resonance structure of the CH chromophore spectra (about 50 assigned bands) is given in terms of an effective anharmonic CH-stretching-bending Hamiltonian and in terms of vibrational variational calculations on a 3-dimensional grid using ab initio (MP2 and B3LYP) and empirically adjusted potential hypersurfaces for the CH chromophore normal coordinate subspace.The systematic analysis of anharmonic resonances of the alkyl CH chromophore in symmetric top (C3v) and asymmetric top (Cs) molecules is herewith extended to chiral molecules.We provide a detailed analysis of the chiral Cs symmetry breaking coupling in the effective Hamiltonian (coupling constant /k'sab/ ca. (20 +/- 10) cm-1) and in the potential (Csab and further terms) and their relationship.The implications for the femtosecond intramolecular dynamics for CHBrClF are discussed in terms of quantum dynamical results for time-dependent populations, survival probabilities, wavepackets and also time-dependent symmetries and their violations (formal a' and a'' species for vibrational Cs and l quantum number for vibrational Cinfinite v symmetry).We have also developed an improved synthesis of CHBrClF, which is suitable for the preparation of large quantities (several mol) of the pure (racemic) compound, and have demonstrated enantiomer separation by gas chromatography. - Keywords: Chemical Kinetics; Elementary Reactions; Intramolecular Kinetics; Molecular Structure; Spectroscopy, Infrared; Wave Functions
A Facile Synthesis of Fluorochlorobromoacetic Acid
Doyle, Thomas R.,Vogl, Otto
, p. 31 - 43 (2007/10/02)
Fluorochlorobromoacetic acid was synthesized in the sequence of four steps from 1,1,2-trifluoro-2-chloroethylene in an overall yield of approximately 25percent. 1,1,2-Trifluoro-2-chloroethylene was first allowed to react with sodium methoxide to form 1,2-difluoro-1-chloro-2-methoxyethylene, which was then brominated with elemental bromine and the reaction product treated with concentrated sulfuric acid to give methyl fluorochlorobromoacetate.This compound was hydrolized with a diluted sodium hydroxide solution to fluorochlorobromoacetic acid.
