Acetaldehyde synthesis from acetylene

Acrolein and condensable by-products, mainly acrylic acid plus some acetic acid and acetaldehyde, are separated from nitrogen and carbon oxides in a water absorber. However in most industrial plants the product is not isolated for sale, but instead the acrolein-rich effluent is transferred to a second-stage reactor for oxidation to acrylic acid. In fact the volume of acrylic acid production ca. 4.2 Mt/a worldwide) is an order of magnitude larger than that of commercial acrolein. The propylene oxidation has supplanted earlier acrylic acid processes based on other feedstocks, such as the Reppe synthesis from acetylene, the ketene process from acetic acid and formaldehyde, or the hydrolysis of acrylonitrile or of ethylene cyanohydrin (from ethylene oxide). In addition to the (preferred) stepwise process, via acrolein (Equation 30), a... 

Vinyl acetate, CH2=CH—OOC—CH3, is produced from ethylene and acetic acid or from acetaldehyde and acetic anhydride. The previously extensively used synthesis from acetylene and acetic acid is now too expensive. 

The principle of this method has been utilised on the industrial scale, and with success for the preparation of acetone. The acetic acid may be prepared from acetylene via acetaldehyde (see p. 433), thus providing a commercial synthesis of acetone from coke. 

Copper chloride complexes can be used as catalysts in a number of organic reactions. Examples include the Wacker process, which is the oxidization of ethylene to acetaldehyde by oxygen and aqueous Cu and Pd precatalysts (or, alternatively using iron catalysts) plus the synthesis of acrylonitrile from acetylene and hydrogen cyanide using CuCl. Cuprous chloride has also been used as a desulfiuizmg and... 

Although alcohol has been produced by the hydrogenation of acetaldehyde obtained from the hydration of acetylene, this source is relatively unimportant ordinarily. It does, however, furnish a means for the synthesis of ethanol from such sources of carbon as calcium carbide, methane, the carbon arc, etc., which might become of importaice during periods of war, or in locations where very cheap electric power is available. Experiments on a technical scale78 in Switzerland have shown the process to be successful but at a cost too high to make the process competitive. 

In 1893, the French chemist Moreau described two routes for the synthesis of acrylonitrile that were based on the dehydration of either acrylamide or ethylene cyanohydrin [10]. There was very little interest in acrylonitrile until 1937 when synthetic rubber based on acrylonitrile-butadiene copolymers was first developed in Germany. A process based on the addition of hydrogen cyanide to acetylene was developed at that time and in the 1950s, the acrylic fiber industry provided the stimulus for further process developments. Today acrylonitrile is made commercially by one of three possible methods (a) from propylene, (b) from acetylene and hydrogen cyanide, and (c) from acetaldehyde and hydrogen cyanide. 

Write a synthesis for this compound from acetylene, acetaldehyde, and iodomethane. Unless otherwise noted all art on this page Cengage Learning 2013... 

Since 1960, the Hquid-phase oxidation of ethylene has been the process of choice for the manufacture of acetaldehyde. There is, however, stiU some commercial production by the partial oxidation of ethyl alcohol and hydration of acetylene. The economics of the various processes are strongly dependent on the prices of the feedstocks. Acetaldehyde is also formed as a coproduct in the high temperature oxidation of butane. A more recently developed rhodium catalyzed process produces acetaldehyde from synthesis gas as a coproduct with ethyl alcohol and acetic acid (83—94). 

Other synthetic methods have been investigated but have not become commercial. These include, for example, the hydration of ethylene in the presence of dilute acids (weak sulfuric acid process) the conversion of acetylene to acetaldehyde, followed by hydrogenation of the aldehyde to ethyl alcohol and the Fischer-Tropsch hydrocarbon synthesis. Synthetic fuels research has resulted in a whole new look at processes to make lower molecular weight alcohols from synthesis gas. 

A number of routes are available for the synthesis of 2,2 -bipyridines where one of the pyridine rings is built up from simpler entities. For example, condensation of 2-(aminomethyl)pyridine (31) with acetaldehyde or acetylene over a silicon-alumina catalyst at 450°C gives 2,2 -bipyridine, ° whereas 2-cyanopyridine reacts with acetylene at 120°C in the presence of a cobalt catalyst to afford 2,2 -bipyridine in 95% yield.2-Acetylpyridine with acrolein and ammonia gives 2,2 -bipyridine in the presence of dehydrating and dehydrogenating catalysts, and related condensations afford substituted 2,2 -bipyridines. ° In a similar vein, condensation of benzaldehyde with 2 mol of 2-acetylpyridine in the presence of ammonia at 250°C affords 2,6-di(2-pyridyl)-4-phenylpyridine, ° and related syntheses of substituted 2,2 6, 2"-terpyridines have been described. Likewise, formaldehyde with two moles of ethyl picolinoylacetate and ammonia, followed by oxidation of the product and hydrolysis and decarboxylation, affords a good... 

The synthesis of acetaldehyde by oxidation of ethylene, generally known as the Wacker process, was a major landmark in the application of homogeneous catalysis to industrial organic chemistry. It was also a major step in the displacement of acetylene (made from calcium carbide) as the feedstock for the manufacture of organic chemicals. Acetylene-based acetaldehyde was a major intermediate for production of acetic acid and butyraldehyde. However the cost was high because a large energy input is required to produce acetylene. The acetylene process still survives in a few East European countries and in Switzerland, where low cost acetylene is available. 

Ethanol is the key reactant in Eq. (1), and also in Eq. (2) because it is readily converted to acetaldehyde. The process based on Eq. 1 was developed in Russia and the process based on Eq. 2 was developed in the United States. The yield of butadiene for the Russian process is about 30-35%. It is about 70% if mixtures of ethanol and acetaldehyde are employed as in the U.S. process. Equation (3) represents a process that involves 2,3-butylene glycol, a product from the microbial conversion of biomass. The process is carried out in two sequential steps via the glycol diacetate in overall yields to butadiene of about 80%. The process of Eq. (4) starts with a biomass derivative, the cyclic ether tetrahydrofuran, and can be carried out at high yields. When this process was first operated on a large scale in Germany, acetylene and formaldehyde were the raw materials for the synthesis of intermediate tetrahydrofuran. It is manufactured today from biomass feedstocks by thermochemical conversion, as will be discussed later. 

EINECS 231-992-5 HSDB 1247 Mercuric bisulphate Mercuric sulfate Mercuric sulphate Mercurous bisulphate Mercury bisulfate Mercury disulfate Mercury persulfate Mercury sulfate (HgSOk) Mercury sulphate Mercury(ll) sulfate Mercury(ll) sulfate (1 1) Sulfate mercurique Sulfuric acid, mercury(2- ) salt (1 1). Catalyst in the conversion of acetylene to acetaldehyde, extracting gold and silver from roasted pyrites, battery electrolyte. Solid dec 450 d = 6.47 reacts with H2O LDm (rat orl) n 57 mg/kg. Atomargic Chamatals Lancaster Synthesis Co. Noah Cham. 

While this synthesis lacks industrial significance at present, it is of interest in that it makes it possible to synthesize the rubber from coal, through the preparation of calcium carbide, acetylene, and acetaldehyde. These latter steps in the process have been put on an industrial basis. 

Depending on the reaction conditions, ethylidine diacetate can be the major product of the metal-catalyzed reaction of acetylene with acetic acid and is also a byproduct of the oxidative acylation of ethylene. In addition, ethylidine diacetate is readily prepared by the reaction of acetaldehyde with acetic anhydride (37). A commercial-scale synthesis of vinyl acetate developed and piloted by the Celenese Corporation involved the pyrolysis of ethylidine diacetate obtained from acetaldehyde (38) [219,220]. 

The first commercial plant for the chemical production of acetic acid came on line in 1916. Qearly, this was the beginning of the expanding market for acetic add as an important commodity chemical in industry (Agreda and Zoeller 1993). Chemical synthesis of acetic acid is dependent upon petrochemicals from nomenewable crude oil resources. There are three major processes in use today oxidation of acetylene-derived acetaldehyde, catalytic butane oxidation, and the carbonylation of methanol (the Monsanto process Agreda and Zoeller 1993). Production hy the Monsanto process provides the major source of glacial acetic add used in industry worldwide. In the United States, chemical synthesis of acetic acid was reported as 2.34 x 10 t/year in 1995 (Kirschner 1996), which demonstrates the importance of acetic acid as a commodity chemical in industry. 

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