Ethane derivatives

A number of 1,2,3-oxathiazole 5-oxides are prepared from the reaction of thionyl chloride with various ethane derivatives having vicinal oxygen- and nitrogen-containing groups. Reaction of the 2-aminoethanol derivative (146) with SOCI2 gave (147) (see Chapter 4.34). 

The hydrogenation of pyrazolylacetylenes shows no peculiarities. Ethynylpyra-zoles are hydrogenated in high yields to the corresponding ethane derivatives on Raney nickel catalyst, platinum dioxide, or palladium catalyst at room temperature in alcohol solution. 

Polya also obtained asymptotic estimates for a number of other problems, such as multiply-substituted alkanes, ethane derivatives, and cycloparaffins. 

The proposed polymerization mechanism is shown in Scheme 9.12. Thermal decomposition of the hexasubstituted ethane derivative yields hindered tertiary radicals that can initiate polymerization or combine with propagating species (primary radical termination) to form an oligomeric macroinitiator. The addition of the diphenylalkyl radicals to monomer is slow (e.g. k[ for 34 is reported as KT M"1 s l at 80 °C84) and the polymerization is characterized by an inhibition period during which the initiator is consumed and an oligomeric macroinitiator is formed. The bond to the Cl I formed by addition to monomer is comparatively thermally stable. 

Few SF5-substituted saturated hydrocarbons have been reported. On the basis of the methane and ethane derivatives in Scheme 7.22, it appears as if the equatorial b-fluorines of the ab4 system are much more... 

The chemical structure for common chlorinated solvents is shown in Figure 4.5. Chlorinated solvents such as TCE and PCE are composed of double-bonded carbon or ethylene structures with three and four chlorine atoms, respectively. The ethane derivative 1,1,1-TCA has three chlorine atoms. Freon is a chlorofluorocarbon and is also an ethane derivative with four chlorine atoms and three fluoride atoms. 

Diethyl ether was the inhalation anesthetic of choice during my childhood. Happily, 1 had rather little need of it. Ether was replaced years ago by a family of superior inhaled general anesthetics, most of which are ethane derivatives. The notable exception is another very simple molecule, nitrous oxide, N2O, frequently known as laughing gas. N2O has been around for a long time and was once a party drug. ... 

Let s have a look at some of the ethane derivatives. Perhaps the simplest of these is halothane ... 

Chloral Hydrate. (An ethane derivative.) Chloral hydrate is one of the easiest drugs to make in this entire book. It is an effective hypnotic, that is rapidly absorbed from the stomach, and produces dulled sensoiy and motor functions, that last for 6 to 8 hours. The dose is from 250 mg to 1,500 mg. Chloral can be purchased at most any chemical supply house, eliminating the need for performing the first part of this synthesis. Chloral is not very suspicious (unless you re buying it by the 55 gallon drum), so you should have no trouble in making chloral hydrate directly from chloral. 

Dtatmno-l-alkenes. Doss Bost (Ref 1) describe the prepn of 1, 2-bis(dimethyl-amino) ethylene (bp 38-40° at 15mm l, s 4648), its hydrogenation in a Parr bomb at 40lb/sq inch to the ethane (nfi 1.4170) and the use of the ethane deriv as a component of hypergolic fast-burning rocket fuels... 

Several recent reports by the World Health Organization have dealt with environmental health criteria of fluorocarbons fully halogenated chlorofiuorocarbons,76 partially halogenated chlorofiuorocarbons (methane derivatives),77 and partially halogenated chlorofiuorocarbons (ethane derivatives).78 183 185... 

Partially Halogenated Chlorofluorocarhons (Ethane Derivatives), Environmental Health Criteria 139 WHO, Ed. Geneva, 1992. 

The direct chlorination of ethane184-186 is used for the manufacture of two ethane derivatives, ethyl chloride and 1,1,1-trichloroethane. Both compounds are important solvent and 1,1,1-trichloroethane is also used as a degreasing agent. 

Figure 9-33 Schematic proton nmr spectra X and Y are nonmagnetic nuclei. For 2-propane derivatives, as at the top, the CH3 resonances are double because of the splitting produced by the single proton on C2. For the ethane derivatives, the right set of lines is always a triplet when observable because of the two protons of the X—CH2— group. We assume here that the chemical shifts of the CH Y3 protons are independent of the number of Y substituents.

A few examples of propane and butane derivatives are included in Table 4. The results obtained for such molecules are, as a whole, in accordance with what should be expected from the study of ethane derivatives. 

Ethane occurs in natural gas, from which it is isolated. Ethane is among the chemically less reactive organic substances. However, ethane reacts with chlorine and bromine to form substitution compounds. Ethyl iodide, bromide, or chlorides are preferably made by reaction with ethyl alcohol and the appropriate phosphorus halide. Important ethane derivatives, by successive oxidation, are ethyl alcohol, acetaldehyde, and acetic acid. Ethane can also be used for the production of aromatics by pyrolysis (Fig. 1). 

Disilanes and trisilanes with olefinic substituents (such as vinyl- and allyl-disilanes) react in the presence of H2PtCl6 6 H20 undergoing a Si-Si cleavage692. A second reaction sometimes occurs so that simple cleavage products are not obtained. For example, vinylpentamethyldisilane reacts with the cleavage product trimethylsilane, giving an ethane derivative ... 

The high coupling performance, apparent from total yields of isolable coupling products of 60-70%, has also been found for the dimerization of tetraethinyl-ethane derivative 17 to the cyclic diastereoisomers syn-18 and anti-18 (Scheme 8) [61-... 

When all the rotations are possible in the solid state the symmetry increases to hexagonal. This form corresponds to the close packing of spheres or cylinders and the molecule is in a rotational crystalline state, characterized by rigorous order in the arrangement of the center (axes) of the molecules and by disordered azimuthal rotations [118]. If the chain molecules are azimuthally chaotic (they rotate freely around their axes), their average cross sections are circular and, for this reason, they choose hexagonal packing. The ease of rotation of molecules in the crystal depends merely on the molecular shape, as in molecules of an almost spherical shape like methane and ethane derivatives with small substituents, or molecules of a shape close to that of a cylinder (e.g., paraffin-like molecules). 

Finally, as shown by Kabalka and Yao [131] bis(pinacolato)diboron can be applied in a sequential Pd-catalyzed Miyaura borylation and Suzuki coupling to a (bromomethylene)cyclobutane furnishing an efficient synthesis of the (dicyclobutylidene)-ethane derivative 184, whereas the presumed boronate intermediate 185 was only obtained in trace amounts (Scheme 72). 

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