Isobutyl acetylene

Chemicals. Although the amount of butylenes produced ia the United States is roughly equal to the amounts of ethylene and propylene produced, the amount consumed for chemical use is considerably less. Thus, as shown ia Table 10, the utilisation of either ethylene or propylene for each of at least five principal chemical derivatives is about the same or greater than the utilisa tion of butenes for butadiene, their main use. This production is only about one-third of the total the two-thirds is derived directiy from butane. The undedyiag reasons are poorer price—performance compared to derivatives of ethylene and propylene and the lack of appHcations of butylene derivatives. Some of the products are more easily derived from 1-, 2-, and 3-carbon atom species, eg, butanol, 1,4-butanediol, and isobutyl alcohol (see Acetylene-DERIVED chemicals Butyl alcohols). 

Although APDC complexes are soluble in many organic solvents, it is found that 4-methylpent-2-one (isobutyl methyl ketone) and heptan-2-one (n-pentyl methyl ketone) are, in general, the most satisfactory for direct nebulisation into the air/acetylene flame used in atomic absorption spectroscopy. 

Solutions in organic solvents may, with certain reservations, be used directly, provided that the viscosity of the solution is not very different from that of an aqueous solution. The important consideration is that the solvent should not lead to any disturbance of the flame an extreme example of this is carbon tetrachloride, which may extinguish an air-acetylene flame. In many cases, suitable organic solvents [e.g. 4-methylpentan-2-one (methyl isobutyl ketone) and the hydrocarbon mixture sold as white spirit ] give enhanced production of ground-state gaseous atoms and lead to about three times the sensitivity... 

Dimethyl sulfate Sulfuric acid, dimethyl ester (8,9) (77-78-1) Isobutyl methyl ketone 2-Pentanone, 4-methyl- (8, 9) (108-10-1) Acetylene, diphenyl- (8) Benzene, , -(l,2-ethynediyl)bis- (9) (501-65-5)... 

Atomic absorption spectrometry coupled with solvent extraction of iron complexes has been used to determine down to 0.5 pg/1 iron in seawater [354, 355]. Hiire [354] extracted iron as its 8-hydroxyquinoline complex. The sample is buffered to pH 3-6 and extracted with a 0.1 % methyl isobutyl ketone solution of 8-hydroxyquinoline. The extraction is aspirated into an air-acetylene flame and evaluated at 248.3 nm. 

Devoto 115)has described an indirect procedure for the determination of 0.1 ppm arsenic in urine. The arsenomolybdic acid complex is formed and extracted from 1 ml of urine at pH 2 into 10 ml of cyclohexanone. The molybdenum in the complex is then measured. Before extracting the arsenic, phosphate in the urine is separated by extracting the phosphomolybdic acid complex at pH 1 into isobutyl acetate. The direct determination of arsenic in biological material and blood and urine is best done using a nitrous oxide-acetylene flame 116>. The background absorption by this flame is low at 1937 A, and interferences are minimized due to the high temperature of the flame. 

The cis-fagaramide (J) was synthesized as outlined below. The required acetylenic acid (c) was prepared from piperonal (a) by the Corey s procedure.Treatment of piperonal with carbon tetrabromide, triphenylphosphine and zinc gave the bromo olefin (b) as an oil in 71% yield. The bromo olefin (b) was treated with 2 equivalents of n-butyl lithium followed by quenching with dry ice to give acetylenic acid (c) in 54% yield. Treatment of (c) with excess thionyl chloride without solvent at 50 followed by addition of isobutyl amine in benzene gave the acetylenic amide (d) as a viscous oil in 96% yield. Partial reduction of (d) gave cis-fagarmide (7 ) in 89% yield. 

LXVIII), a constituent of aviation fuel. The reaction of acetone with acetylene may also lead to developments of importance in finding new uses for acetone. For example, acetone reacts with acetylene in the presence of a metal acetylide catal5rst to form the compound LXIX, which could be converted into isopentane (LXX), another constituent of aviation fuel. There may be possibilities of using the condensation products of acetone such as mesityl oxide (LXXI), which could be converted through the saturated ketone, methyl isobutyl ketone (LXXII), into 4-methylpentane (LXXIII). 

Molybdenum may be identified at trace concentrations by flame atomic absorption spectrometry using nitrous oxide-acetylene flame. The metal is digested with nitric acid, diluted and analyzed. Aqueous solution of its compounds alternatively may be chelated with 8—hydroxyquinobne, extracted with methyl isobutyl ketone, and analyzed as above. The metal in solution may also be analyzed by ICP/AES at wavelengths 202.03 or 203.84 nm. Other instrumental techniques to measure molybdenum at trace concentrations include x-ray fluorescence, x-ray diffraction, neutron activation, and ICP-mass spectrometry, this last being most sensitive. 

This preparation works equally well for the isobutyl and isohexyl homologs. For /3-chlorovinyl methyl ketone, which is both a lachrymator and a vesicant, the initial rapid rate of absorption of acetylene begins only after 3-9 hours. 

When (67) was treated with a wide variety of cycloaddition reagents under various conditions, it behaved as a diene or a dienophile but not as a 1,3-dipole. As a dienophile it reacted with 2,3-dimethyl-1,3-butadiene to give (70) and with cyclopentadiene to give an analogous product. As a diene it reacted with [2.2.1] bicycloheptene to give (72), presummably via (71), by loss of carbon monoxide and hydrogen. No products were isolated when (67) was treated with maleic anhydride, dimethyl acetylene-dicarboxylate, diphenylacetylene, dimethyl fumarate, carbon disulfide, isobutyl vinyl ether, cyclohexene, and cyclopentene. 

Methyl acetylene Methyl isobutyl ketone Methyl cyclopentane Tetrahydrofuran... 

Using any necessary inorganic reagents, show how you would convert acetylene and isobutyl bromide to... 

A new approach to /3-alkyl substituted a-methoxy vinyllithiums 540 with Z-configuration involved the stereoselective metallation of a-bromo vinyl ethers 539, prepared from acetylenes 538, with f-BuLi at — 78 °C (Scheme 145)821. These anions react with different electrophiles to give the corresponding vinyl ethers in good yields. The /3-isobutyl substituted derivative as cuprate has been added to an enone in the total synthesis of the anticancer natural product OSW-1822. 

The reduction of acetylenic Mannich bases exhibits several interesting stereochemical features. The triple bond can be partially hydrogenated with di-isobutyl aluminum hydride, thus giving E-allylamines 293. This reagent provides very good stereoselectivity, the mechanism of which has been investigated. - ... 

Derivation Catalytic union of acetylene and isobutyl alcohol. 

Acetone is used as a solvent for cellulose acetate, nitrocellulose and acetylene as a raw material for the chemical synthesis of such products as ketones, acetic anhydride, methyl methacrylate, bisphenol-A, diacetone alcohol, methyl isobutyl ketone, isophorone, etc. 

The difference in behavior of ethylene and acetylene with triisobutylalane is shown by the fact that, with ethylene, the isobutyl radical is removed very easily as isobutene. 

Commercial uses have developed for several poly(vinyl ethers) in which R is methyl, ethyl, and isobutyl. The vinyl alkyl ether monomers are produced from acetylene and the corresponding alcohols, and the polymerization is usually conducted by cationic initiation using Friedel-Craft-type catalysts. 

At extremely low concentration, silver can be chelated with ammonium pyrrolidine dithio-carbamate, extracted into methyl isobutyl ketone, aspirated into an air-acetylene flame, and measured by AAS. This procedure concentrates the sample, thus extending the detection limits. 

---