Acetylene derivs synthesis

Historically, the use of acetylene as raw material for chemical synthesis has depended strongly upon the avadabihty of alternative raw materials. The United States, which until recendy appeared to have limitless stocks of hydrocarbon feeds, has never depended upon acetylene to the same extent as Germany, which had more limited access to hydrocarbons (1). During Wodd War 1 the first manufacture of a synthetic mbber was undertaken ia Germany to replace imported natural mbber, which was no longer accessible. Acetylene derived from calcium carbide was used for preparation of... 

Acetylene is used primarily as a raw material for the synthesis of a variety of organic chemicals (see AcETYLENE-DERiVED CHEMICALS). In the United States, this accounts for about 80% of acetylene usage and most of the remainder is used for metal welding or cutting. The chemical markets for acetylene are shrinking as ways are found to substitute lower cost olefins and paraffins for the acetylene, with some products now completely derived from olefinic starting materials. Metalworking appHcations, however, have held up better than chemical uses. 

S. F. Vasilevsky and E. V. Tetryakov (Novosibirsk, Russia), together with J. Elguero (Madrid, Spain), have summarized the synthesis, chemical and spectroscopic properties, and biological activity of acetylenic derivatives of pyrazoles, a field which has shown explosive growth in the past few years. 

As shown by the Italian school, the formation of isoxazole derivatives by the action of nitric acid or nitrogen oxides on acetylene derivatives and related reactions proceeds through intermediate nitrile oxides and must, therefore, be included with this type of synthesis. 

Ebdon and coworkers22 "232 have reported telechelic synthesis by a process that involves copolymerizing butadiene or acetylene derivatives to form polymers with internal unsaturation. Ozonolysis of these polymers yields di-end functional polymers. The a,o>dicarboxy1ic acid telechelic was prepared from poly(S-s tot-B) (Scheme 7.19). Precautions were necessary to stop degradation of the PS chains during ozonolysis. 28 The presence of pendant carboxylic acid groups, formed by ozonolysis of 1,2-diene units, was not reported. 

Figure 5.5 Cost Index in the synthesis of the acetylene derivatives 1 (Scheme 5.2), using the software EATOS. Prices according to the Aldrich catalog (2002) were used. For a description of the synthesis a) to b) see Figure 5.4. The price of the imines was not considered.

An important synthesis method of organogermanes is the hydrogermylation of olefinic and acetylenic derivatives in the presence of a catalyst. Examples of such reactions are listed below38 ... 

Synthetic rubber(s), 1 693, 21 761. See Ethylene-propylene polymers. See also Butyl rubber acetylene-derived sources, 1 228 synthesis of first butyl rubber after disruption of natural rubber supply in WW II, 4 433... 

Cassar, J. Synthesis of Aryl- and Vinyl-substituted Acetylene Derivatives by the Use of Nickel and Palladium Complexes, J. Organomet. Chem. 1975,93, 253. 

Dieck, H. A. Heck, F. R. Palladium Catalyzed Synthesis of Aryl, Heterocyclic and Vinylic Acetylene Derivatives, J. Organomet. Chem. 1975, 93, 259. 

Alcohol Standards. The alcohols chiefly used are the acetylene derivates 1-butanol, 2-ethylbutanol, 1-hexanol, 2-ethylhexanol, and isononyl alcohol produced from octene by the oxo synthesis. 

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