Aliphatic and Cycloaliphatic Compounds

ACYLATION OF ALIPHATIC COMPOUNDS Similar to alkylation, not only aromatic but also aliphatic and cycloaliphatic compounds undergo Friedel-Crafts acylation reactions. 

C Light naphtha (mainly Cs-Ce) C4-C10 aliphatic and cycloaliphatic compounds. May contain some aromatics. Useful for both fuel and chemicals. 

In aliphatic and cycloaliphatic compounds, vicinal carbon-proton coupling constants 3Jch are related to the dihedral angle 0, as known from the Karplus-Conroy relation for iJ[iH. The Fermi-contact contribution to 3JCH as a function of the dihedral angle 0 calculated for propane [131] is displayed in Fig. 3.15, and the Karplus relation given by eq. (3.17) can be derived ... 

The organohalogen FRs can be classified into three groups aromatic, aliphatic, and cycloaliphatic compounds. The halogen is either chlorine or bromine. Fluorinated compounds are expensive and generally not effective iodinated compounds are effective but unstable and are therefore not used. 

As shown in Table 8, the spray paint solvent is predominately a mixture of several linear aliphatic, branched aliphatic, and cycloaliphatic hydrocarbons, and toluene, xylenes, and ethyl benzene. 2-Butanone (also known as methyl ethyl ketone) was also detected. The breakdown of the solvent mixture by class of compound (aromatic, //-alkane, iso-alkane, cyclic alkane, and others) is shown in Table 9. The solvent appears to be consistent with a mixture of a VM P naphtha... 

Aliphatic and Cycloaliphatic Resins. Aliphatic and cycloaliphatic epoxy resins have been produced from the epoxidation of olefinic compounds. The epoxidation process involves the use of an olefinic or polyolefinic compound and a peracid (e.g., peracetic acid) or other... 

Changes in monomer concentration also have an effect on product quality. High butadiene content causes the formation of gel that can coat the walls of the reaction vessel and the pipeline consequently the path of operation is disrupted. In practice, up to 15 % butadiene is loaded in the solvent. Aromatic compounds (especially benzene) are used as the solvent, as in Ti-BR production. By adding small amounts of R3AI (R = C8-C12) the polymerization can also be carried out in aliphatic and cycloaliphatic solvents without any gel formation. 

There is very little information about halogenated aliphatic and cycloaliphatic epoxy compounds. Brominated epoxy compounds were prepared by the addition of Br to the cyclohexenyl double bond in a diglycidyl ether in mild conditions (Scheme 60) [39]. 

The different reactivity of the aliphatic and cycloaliphatic epoxy groups in ACECs can be used for the synthesis of functionalized compounds with the cycloaliphatic epoxy groups preserved. As an example, an epoxy group containing polyhydric alcohol XLVII is presented (Scheme 62). The epoxy polyol XLVII was applied for the modification of isocyanates on purpose to obtain flexible coatings with good protective properties. 

Curing agents are used with epoxy resins, the most commonly used ones are aromatic amines, and two of the most common are 4,4-methylene-dianiline (MDA) and 4,4-sulfonyl-dianiline (DDS). Like the epoxies, these compounds have very low vapour pressures and in principle they should not present any airborne hazard, unless a mixture is sprayed or cured at high temperatures and certainly potential for dermal exposure is high. Several other types of curing agents to consider are aliphatic and cycloaliphatic amines, polyaminoamides, amides, and anhydrides. 

The spray paint can was inverted and a small amount of product was dispensed into a 20 mL glass headspace vial. The vial was immediately sealed and was incubated at 80°C for approximately 30 min. After this isothermal hold, a 0.5-mL portion of the headspace was injected into the GC/MS system. The GC-MS total ion chromatogram of the paint solvent mixture headspace is shown in Figure 15. Numerous solvent peaks were detected and identified via mass spectral library searching. The retention times, approximate percentages, and tentative identifications are shown in Table 8 for the solvent peaks. These peak identifications are considered tentative, as they are based solely on the library search. The mass spectral library search is often unable to differentiate with a high degree of confidence between positional isomers of branched aliphatic hydrocarbons or cycloaliphatic hydrocarbons. Therefore, the peak identifications in Table 8 may not be correct in all cases as to the exact isomer present (e.g., 1,2,3-cyclohexane versus 1,2,4-cyclohexane). However, the class of compound (cyclic versus branched versus linear aliphatic) and the total number of carbon atoms in the molecule should be correct for the majority of peaks. 

Quaternary Ammo nium Compounds. These contain aliphatic and/or cycloaliphatic radicals (R1 -R4 in Eq. 1), of which at least one is a long-chain alkyl radical (with more than five C atoms). The compounds react with the dyes in accordance with the following pattern ... 

The bromination with alkali hypobromite in aqueous solution gives good results with (hetero)arylacetylenes, enynes (RCH=CHCsCH) and diynes (RC=CC=CH), all acetylenes that are more acidic than those acetylenes in the aliphatic or cycloaliphatic series with an isolated triple bond. For the conjugated systems the hypobromite method is superior to the reaction of metallated acetylenes with bromine. Various acetylenic alcohols are also brominated smoothly, which can be explained in part by their better solubility in water. Since in the case of primary and secondary ethynyl alcohols, oxidation of the alcohol can occur, the use of an excess of hypobromite should be avoided. The best procedure is dropwise additon of a small short measure of hypobromite to a mixture of alcohol and water. If the bromoalkynes to be prepared are not too volatile, small amounts of THF or dioxane may be added to effect a better solubility of the alkyne in the aqueous phase. Addition of a co-solvent may also be desired when the starting compound is a solid (e.g. ethynylcyclohexanol). 

For example, unbranched aliphatic acids with an even number of carbon atoms will be generously represented, while one finds a nearly complete absence of odd-numbered and branched acids. Nature produces an incredible diversity of the most ingeniously constructed cyclic products containing cycloaliphatic, aromatic, or heterocyclic moieties, but such derivatives like aniline or thiophe-nol, as well as plethora of other simple representatives of these classes, are not in the list of naturally occurring substances. Such important types as alkyl halides, nitro compounds, and diazo compounds would be sparsely represented by very rare (if any) examples. Even the simplest compounds like formaldehyde, chloroform, diethyl ether, dioxane, etc., which are trivial to organic chemists, turn to be rather exotic for Nature. In the list of items provided by Nature one will notice the almost complete absence of various organometallic compounds, as well as many other classes of structures of immense scientific and practical significance. 

As you now know, aliphatic organic compounds belong to the alkane, alkene, and alkyne classes of compounds. Aliphatic explosives fall into both the open-chain and cycloaliphatic groups. The major sources of oxidizer in most aliphatic explosives are from the nitrate ester group (—ONO2) and the nitramine group (—NH—NO2). The nitrate esters are usually made by direct nitration of an... 

Composites Prepared from Cycloaliphatic and Aliphatic-Cydoaliphatic Epoxy Compounds Crosslinked with Phenol-Formaldehyde Oligomers... 

Flame retardants are required for high-performance thermoplastic resins because of the use of the resins in electrical and high-temperature applications. Numerous chemicals are used as flame retardants. Chlorine-and bromine-containing aliphatic, cycloaliphatic and aromatic compounds are the most widely used. Others are antimony trioxide, aluminum hydrate and chlor-paraffins. A more fire-resistant epoxy resin can be produced by bromating bisphenol A in epoxy resins to tetrabromobisphenol A. 

A free-flowing chlorine-containing cycloaliphatic compound (Occidental s Dechlorane Plus - a diadduct of hexachlorocyclopentadiene and 1,5-cyclooctadiene) can be used with antimony oxide, and also with other synergists, and is particularly effective in nylon 6 and 66 and epoxies. Its aliphatic rather than aromatic structure does not absorb UV radiation, so reducing the potential for discolouration after prolonged ageing. 

The reactive groups attached to the molecules of an epoxy resin can react with several curing agents, such as amines, anhydrides, acids, mercaptans, imidazoles, phenols and isocyanates, to create covalent intermolecular bonds and thus to form a three-dimensional network. Among these compounds, due to the enhanced environmental stability of amine-cured epoxy resin (Dyakonov et al., 1996), primary and secondary amines are the curing agents most commonly used in particular aliphatic or cycloaliphatic amines for low-temperature epoxy systems as adhesives or coatings and aromatic amines to produce matrices for liber-reinforced composites (Pascault and Williams, 2010). In Fig. 5.14 the structures of both an aliphatic and an aromatic amine are shown. 

Aliphatic-cycloaliphatic epoxy compounds (ACECs) contain dilferent epoxy groups in the molecule glycidyl, i.e., 2,3-epoxypropyl groups, and cycloaliphatic, i.e., 1,2-epoxycyclo-pentane or 1,2-epoxycyclohexane rings, for which molecules 3 and 4 are characteristic. 

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