Acetylene 1-butene from

Catalytic forms of copper, mercury and silver acetylides, supported on alumina, carbon or silica and used for polymerisation of alkanes, are relatively stable [3], In contact with acetylene, silver and mercury salts will also give explosive acetylides, the mercury derivatives being complex [4], Many of the metal acetylides react violently with oxidants. Impact sensitivities of the dry copper derivatives of acetylene, buten-3-yne and l,3-hexadien-5-yne were determined as 2.4, 2.4 and 4.0 kg m, respectively. The copper derivative of a polyacetylene mixture generated by low-temperature polymerisation of acetylene detonated under 1.2 kg m impact. Sensitivities were much lower for the moist compounds [5], Explosive copper and silver derivatives give non-explosive complexes with trimethyl-, tributyl- or triphenyl-phosphine [6], Formation of silver acetylide on silver-containing solders needs higher acetylene and ammonia concentrations than for formation of copper acetylide. Acetylides are always formed on brass and copper or on silver-containing solders in an atmosphere of acetylene derived from calcium carbide (and which contains traces of phosphine). Silver acetylide is a more efficient explosion initiator than copper acetylide [7],... 

The arylacetylene phenylheptatriyne (Phe—C=C—C=C—C=C—CH 3) from Bidens, Dahlia and Coreopsis species (Asteraceae) has phototoxic antimicrobial activity as have 5-(3-buten-l-ynyl)-2,2 -bithienyl (thiophene—thiophene—C=C—C=CH2) and the cyclic disulfide acetylenes thiarubrine A (C3—(C4,S—S)—C6) and thiarubrine B (Cj-(C4,S-S)-C3). The photoactivation of acetylenes derives from light absorption by these conjugated systems and ready reaction with oxygen to form reactive intermediates. 

ACETYLENIC ETHERS FROM ALCOHOLS AND THEIR REDUCTION TO Z-AND E-ENOL ETHERS PREPARATION OF 1-MENTHOXY-1-BUTYNE FROM MENTHOL AND CONVERSION TO (Z)-AND (E)-1-MENTHOXY-1 -BUTENE ([Cyclohexane, 2-(1 -butynyloxy)-4-methyl-1 -(1 -methylethyl)- [1S-(1a,2p,4p)]-], end [[[Cyclohexane, 2-(1-butenyloxy)-4-methyl-1-(1-methylethyl)-, [1S-[1a,2P(Z),4p]]- and [lS-[1 ,2p(E),4P]]-)... 

ACETYLENIC ETHERS FROM ALCOHOLS AND THEIR REDUCTION TO Z- AND E-ENOL ETHERS PREPARATION OF 1-MENTHOXY-1-BUTYNE FROM MENTHOL AND CONVERSION TO (Z)- AND (E)-1 -MENTHOXY-1 -BUTENE... 

Acetylenic Ethers from Alcohols and Their Reduction to Z- and E-Enol Ethers Preparation of 1-Menthoxy-1-butyne from Menthol and Conversion to (Z)- and (E)-1-Menthoxy-1 -butene. 

The effect of nitric oxide or oxygen on the photolysis of cis- or trflnj-butene-2 was quite striking The yields of ethane, propene, -butane, butene-1, isobutane and Cj to Cg compounds were reduced sharply to levels well below those from corresponding runs with nitrogen. In contrast, allene, methane, ethylene, acetylene, butene-2 and butadiene were affected only to the same extent as the runs with nitrogen. It is concluded that the products in the latter group are primary while those of the former group are secondary and arise from free radicals produced in primary steps. 

The problem now is to prepare 1-butene from ethyl bromide and acetylene, a process that clearly requires C—C bond formation. We can do this in two operations, shown retrosyn-thetically as ... 

Hexene from 1-butene and acetylene Decane from 1-butene and acetylene... 

Much more important is the hydrogenation product of butynediol, 1,4-butanediol [110-63-4]. The intermediate 2-butene-l,4-diol is also commercially available but has found few uses. 1,4-Butanediol, however, is used widely in polyurethanes and is of increasing interest for the preparation of thermoplastic polyesters, especially the terephthalate. Butanediol is also used as the starting material for a further series of chemicals including tetrahydrofuran, y-butyrolactone, 2-pyrrohdinone, A/-methylpyrrohdinone, and A/-vinylpyrrohdinone (see Acetylene-DERIVED chemicals). The 1,4-butanediol market essentially represents the only growing demand for acetylene as a feedstock. This demand is reported (34) as growing from 54,000 metric tons of acetylene in 1989 to a projected level of 88,000 metric tons in 1994. 

The pattern of commercial production of 1,3-butadiene parallels the overall development of the petrochemical industry. Since its discovery via pyrolysis of various organic materials, butadiene has been manufactured from acetylene as weU as ethanol, both via butanediols (1,3- and 1,4-) as intermediates (see Acetylene-DERIVED chemicals). On a global basis, the importance of these processes has decreased substantially because of the increasing production of butadiene from petroleum sources. China and India stiU convert ethanol to butadiene using the two-step process while Poland and the former USSR use a one-step process (229,230). In the past butadiene also was produced by the dehydrogenation of / -butane and oxydehydrogenation of / -butenes. However, butadiene is now primarily produced as a by-product in the steam cracking of hydrocarbon streams to produce ethylene. Except under market dislocation situations, butadiene is almost exclusively manufactured by this process in the United States, Western Europe, and Japan. 

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). 

The vinylacetylene [689-97-4] route to chloroprene has been described elsewhere (14). It is no longer practical because of costs except where inexpensive by-product acetylene and existing equipment ate available (see Acetylene-DERIVED chemicals). In the production of chloroprene from butadiene [106-99-0], there are three essential steps, chlorination, isomerization, and caustic dehydrochlorination of the 3,3-dichloro-l-butene, as shown by the following equations Chlorination... 

The principal components of the cut are butene-1, butene-2, isobutylene and butadiene-1,3. Methyl, ethyl, and vinyl acetylenes, butane and butadiene-1,2 are present in small quantities. Butadiene is recovered from the C4 fraction by extraction with cuprous ammonium acetate (CAA) solution, or by extractive distillation with aqueous acetonitrile (ACN). The former process is a liquid-liquid separation, and the latter a vapor-liquid separation. Both take advantage of differences in structure and reactivity of the various C4 components to bring about the desired separation. 

Acetonitrile serves to greatly enlarge the spread of relative volatilities so that reasonably sized distillation equipment can be used to separate butadiene from the other components in the C4 fraction. The polar ACN acts as a very heavy component and is separated from the product without much difficulty.The feed stream is carefully hydrogenated to reduce the acetylene level rerun, and then fed to the single stage extractive distillation unit. Feed enters near the middle of the extractive distillation tower, while (lean) aqueous ACN is added near but not at the top. Butenes and butanes go overhead as distillate, with some being refluxed to the tower and the rest water washed for removal of entrained ACN. 

Tower bottoms-ACN, butadiene, with some butenes and acetylenes - are fed to a recovery/stripping column. The hydrocarbons are taken overhead and then rerun to meet product specifications. The stripping column bottoms, (ACN) is then remrned near the top of the extractive distillation tower. A small slipstream goes to the ACN recovery tower, where solvent is also recovered from the water wash streams. 

Industrial synthesis of nerolidol starts with linalool, which is converted into ger-anylacetone by using diketene, ethyl acetoacetate, or isopropenyl methyl ether, analogous to the synthesis of 6-methyl-5-hepten-2-one from 2-methyl-3-buten-2-ol. Addition of acetylene and partial hydrogenation of the resultant dehydroner-olidol produces a mixture of cis- and trans-nerolidol racemates. 

The production of isoprene from acetylene and acetone is also possible. The acetylene is reacted with acetone to produce 2-methyl-3-butyn-2-ol which, by hydrogenation produces 2-methyl-3-butene-2-ol. Dehydration then yields isoprene. 

Petrov and co-workers polymerized acetylene with simultaneous hydrogenation over nickel or nickel plus zinc chloride and obtained saturated and olefinic products. The ratio of products boiling in the gasoline range to heavier products depended upon the catalyst as well as the pressure. The liquid obtained from nickel consisted of a gasoline obtained in 50 % yield in the runs under atmospheric pressure, and in 70 % yield under 20 atm. pressure. The rest comprised diesel fuel hydrocarbons (292). The structure of the liquid hydrocarbons formed was unaffected by the presence of phosphoric acid or zinc in the catalyst. The gas contained up to 80% butenes, depending upon the conditions. This work of Petrov on the synthesis of hydrocarbons is apparently being continued at the present time. 

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