Other Starting Materials

Carboxylic acid esters, N-tert. alkyl acyl amines and saturated aldehydes are also described as starting materials in the Koch carboxylic acid syntheses. Koch and Haaf [591] carbonylated tert. hexylformiate with formic acid and obtained a mixture of carboxylic acids as follows 15% Cg- and C -acids, 28 % of 2,2-dimethyl valeric acid, 14 % Cg- and Cg-acids and 43 % higher acids, mainly Cja-acids. The carbonylation of tert. hexyl acetate yielded 11 % Cg- and Cg-acids, 33% 2,2-dimethyl valeric acid, 10% Cg- and Cg-acids and 16% higher acids, mainly Cig-acids. 

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Its manufacture begins with the formation of dodecanedioic acid produced from the trimeri2ation of butadiene in a process identical to that used in the manufacture of nylon-6,12. The other starting material, 1,12-dodecanediamine, is prepared in a two-step process that first converts the dodecanedioic acid to a diamide, and then continues to dehydrate the diamide to the dinitrile. In the second step, the dinitrile is then hydrogenated to the diamine with hydrogen in the presence of a suitable catalyst. 

It is also possible to prepare them from amino acids by the self-condensation reaction (3.12). The PAs (AABB) can be prepared from diamines and diacids by hydrolytic polymerization [see (3.12)]. The polyamides can also be prepared from other starting materials, such as esters, acid chlorides, isocyanates, silylated amines, and nitrils. The reactive acid chlorides are employed in the synthesis of wholly aromatic polyamides, such as poly(p-phenyleneterephthalamide) in (3.4). The molecular weight distribution (Mw/Mn) of these polymers follows the classical theory of molecular weight distribution and is nearly always in the region of 2. In some cases, such as PA-6,6, chain branching can take place and then the Mw/Mn ratio is higher. 

As a defined ternary B-C-N compound is not known, other starting materials are to be considered in order to synthesize one of the, yet unknown, La-B-C-N compounds. Solution chemistry routes were successfully performed with tetra-cyanoborates to synthesize the compounds A[B(CN)4] with monovalent A = Li, Ag, Cu cations, and M[B(CN)4]2 with divalent M = Hg, Cu, Zn, Mn cations [47]. 

The reactions encountered so far in this chapter were set up so that all the starting materials were used up at the same time. In other words, there were no leftovers at the end of the reaction. Often, chemical reactions are run with an excess of one or more starting materials. This means that one reactant will run out before the others. The reactant that runs out Is called the limiting reactant because it limits the amount of product that can be made. The other starting materials are said to be in excess. 

Formation of the Tc-C Bond from other Starting Materials. . . . 175... 

Organotechnetium Compounds from Other Starting Materials... 

The precious-metal salts are obtained from Johnson Mathey Co. The commercial salts are sold on the basis of metal contained and may not be quite stoichiometric, such as for RhCl3 -3H20. Other starting materials and solvents are reagent-grade samples used as received from commercial sources. 

The compounds CsCl, CsBr, RbCl, RbBr, CrBr3, and CrCl3 were dried under vacuum at 300 °C for 6 to 12 h. All the other starting materials could be used without further treatment as long as they were kept and handled in a dry atmosphere. 

The synthesis of isoquinolinones by amidoalkylation may also be achieved from other starting materials. N-Substituted derivatives were synthesized by the reaction of arylacetyl chlorides and azomethines in the presence of A1C13 to obtain a number of new compounds, such as 48 (Scheme 13) [75MI1 78ACH(98)315 81MI1 82S216]. 

Ethyl diphenylphosphinite, 131 Hexamethyldisilazane, 141 Thionyl chloride, 297 Zirconium(IV) acetylacetonate, 351 From other starting materials Acetohydroxamic acid, 2 Bis(benzonitrile)dichloropalladium(II), 34... 

From carboxylic acids a-Chloroacetamide, 70 Diazomethane-Alumina, 14 Diphenyldiazomethane, 242 Potassium hydroxide, 258 From other starting materials I-Butyl perbenzoate, 58 Dibromomethyllithium, 93 Di-p,-carbonylhexacarbonyldicobalt, 99... 

Although acetylene still is used in a number of organic syntheses on an industrial scale, its use on a high-tonnage basis has diminished because of the lower cost of other starting materials, such as ethylene and propylene. Acetylene has been widely used in the production of halogen derivatives, acrylonitrile, acetaldehyde, and vinyl chloride. Within recent years, producers of acrylonitrile switched to propylene as a starting material. 

In addition to wood chips, what other starting materials can be used to make paper ... 

Other starting materials can be bark, leaves, straw, flax, cotton, jute, hemp, and used paper. 

Hydrolysis and reacetylation gave the ketone 67, which was protected and oxidised with SeC>2 to give the enone 68. Reduction and deprotection gave 57 R H. The other starting material 59 was also made by a Diels-Alder reaction as described in the workbook. 

Other starting materials for adipic acid include butadiene and 1,4-disubsti-tuted-2-butene, which involves dicarbonylation with palladium chloride. Polar, aprotic, and nonbasic solvents are preferred for this reaction to avoid unwanted side products from hydrogenolysis or isomerization. 

The interaction between a fully occupied MO of the substrate and a fully occupied MO of the other starting material at a single center of each component leads neither to stabilization nor to destabilization (Figure 15.5a). The same is true if both interacting MOs are empty (Figure 15.5c). 

Although the system is not perfect, it has been found to provide useful indications about the question in what applications the properties of some starting material are used to the best advantage and whether this starting material stands a chance in competition with other starting materials. 

Richard followed the course of the reactions of Cr(CO)6 and Mo(CO)6 with hexamethylborazine by UV-vis spectroscopy but although he observed that the intensity of the absorption maximum of the hexacarbonyls at around 290 nm decreased and a new band at around 350 nm appeared, he was unable to identify the new product. Experiments with other starting materials such as norborna-diene chromium and molybdenum tetracarbonyl or tris(aniline) molybdenum tricarbonyl which readily react with arenes by ligand exchange, also failed. The key to success was to use tris(acetonitrile) chromium tricarbonyl as the precursor, which in dioxan under reduced pressure afforded the desired hexamethylborazine chromium tricarbonyl as a stable crystalline solid in 90% yield. This was the breakthrough and, after we had communicated the synthesis and spectroscopic data of the complex in the January issue 1967 of Angewandte Chemie, Richard finished his work and defended his Ph.D. thesis in June 1967. Six months before, in December 1966,1 defended my Habilitation thesis in front of the faculty and became Privatdozent (lecturer) on the 1st of January 1967. 

The other starting materials, the phenols 10, were only in part commercially available. Some of these compounds were synthesized by methods described in the literature, but a greater part of them were unknown and new procedures had to be developped for them. 

In Switzerland, it is quite impossible to achieve this low cost, since coal and other starting materials are so much more expensive. At least twice the above cost would be expected. 

Revision of the synthetic pathway to improve properties, yield, purity, etc. Experiment with other starting materials, catalysts, etc. to see it a better procedure could be used... 

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