Ullman

Ullman reaction The synthesis of diaryls by the condensation of aromatic halides with themselves or other aromatic halides, with the concomitant removal of halogens by a metal, e.g. copper powder thus bromobenzene gives diphenyl. The reaction may be extended to the preparation of diaryl ethers and diaryl thio-ethers by coupling a metal phenolate with an aryl halide. 

Roland E and Kleinschmit P 1996 Zeolites Ullman s Encyclopedia of Industrial Chemistry (5th edn) vol A28, ed B Elvers and S Flawkins (Weinheim VCFI) pp 475-504... 

Ubichromenol synthesis, 3, 752 Ugi reaction, 5, 830 Uliginosin B, bromo-molecular dimensions, 3, 621 Ullman and Fetvadjian synthesis quinolines, 2, 477 Ullman synthesis acridines, 2, 470-benzacridines, 2, 470 Ultraviolet light absorbers in polymers, 1, 397-398 Ultraviolet spectroscopy heterocyclic compounds reviews, 1, 78... 

An aiyl methane- or toluenesulfonate ester is stable to reduction with lithium aluminum hydride, to the acidic conditions used for nitration of an aromatic ring (HNO3/HOAC), and to the high temperatures (200-250°) of an Ullman reaction. Aiyl sulfonate esters, formed by reaction of a phenol with a sulfonyl chloride in pyridine or aqueous sodium hydroxide, are cleaved by warming in aqueous sodium hydroxide. ... 

In a synthesis of decinine a phenol was protected as a methanesulfonate that was stable during an Ullman coupling reaction and during condensation, catalyzed by calcium hydroxide, of an amine with an aldehyde. Aryl methanesulfonates are cleaved by warm sodium hydroxide solution. " ... 

In general, imines are too reactive to be used to protect carbonyl groups. In a synthesis of juncusol, however, a bromo- and an iodocyclohexylimine of two identical aromatic aldehydes were coupled by an Ullman coupling reaction modi-fied by Ziegler. The imines were cleaved by acidic hydrolysis (aq. oxalic acid, THF, 20°, 1 h, 95% yield). Imines of aromatic aldehydes have also been prepared... 

Meehanieal failure is any ehange or any design or manufaeturing error that renders a eomponent, assembly or system ineapable of performing its intended funetion (Ullman, 1992). However, it is also possible to suggest several key aspeets of failure (Bignell and Fortune, 1992) ... 

Ullman (1992) argues that the assumption that stress and strength are of the Normal type is a reasonable one because there is not enough data available to warrant anything more sophisticated. A problem with this is that the Normal distribution... 

For many years in meehanieal design, load variations have been masked by using faetors of safety in a deterministie approaeh, as shown below (Ullman, 1992) ... 

The calculated loading stress, L, on a component is not only a function of applied load, but also the stress analysis technique used to find the stress, the geometry, and the failure theory used (Ullman, 1992). Using the variance equation, the parameters for the dimensional variation estimates and the applied load distribution, a statistical failure theory can then be formulated to determine the stress distribution, f L). This is then used in the SSI analysis to determine the probability of failure together with material strength distribution f S). 

The failure determining stresses are also often loeated in loeal regions of the eomponent and are not easily represented by standard stress analysis methods (Sehatz et al., 1974). Loads in two or more axes generally provide the greatest stresses, and should be resolved into prineipal stresses (Ireson et al., 1996). In statie failure theory, the error ean be represented by a eoeffieient of variation, and has been proposed as C =0.02. This margin of error inereases with dynamie models and for statie finite element analysis, the eoeffieient of variation is eited as Q = 0.05 (Smith, 1995 Ullman, 1992). 

Ullman, D. G. 1992 The Mechanical Design Process. NY McGraw-Hill. 

Ullman type coupling occurs between aryl halides and trifluoromethyl copper species generated by the action of copper iodide on sodium tnfluoroacetate [168, 169] or on methyl fluorosulfonyldifluoroacetate [170] (equation 145) Similarly the pentafluoroethyl group can be introduced from potassium pentafluoropropion-ate [171] (equation 146)... 

In 1896, Graebe and Ullman reported the formation of carbazole (5) by reacting 2-aminodiphenylamine (3) with nitrous acid, followed by the thermolysis of the benzotriazole 4 which resulted. ... 

The Graebe-Ullman carbazole synthesis is normally carried out in sealed tubes and at high temperature. The carbazoles/substituted carbazoles are obtained in general in poor to moderate yields. ... 

The Graebe-Ullman carbazole synthesis has been enmloyed in the preparation of substituted carbolines, as well as indolo[2,3-i] quinolines, which are often difficult to synthesize via other approaches, for example, the Fischer indole process. 

Ullman condensation of m-trifluoromethylaniline (13) with o-iodobenzoic acid in the presence of copper-bronze affords flu-fenamic acid (14). An analogous reaction of o-chlorobenzolc acid with 2,3-dimethylaniline (15) gives mefenamic acid (16) meclofenamic acid (18) is obtained by Ullman condensation employing 2,6-dlchloro-3-methylaniline (17). 

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