Phillips method

TTic mo.st widely used conditions (Phillips method [55]) involve heating the reagents together in the presence of hydrochloric acid, usually around 4. M concentration. As detailed below, it is more difficult to make 2-arylbcnzimidazoles in this way, but application of more vigorous conditions is frequently succe.ssful, e.g. heating in a sealed tube at 180°C in the presence of hydrochloric acid or, better still, substitution of polyphosphoric acid for the hydrochloric acid. Other acidic catalysts have also been found to be effective [56]. 

As it happens, little attention was paid to Phillips discovery because there was not much demand for sulfuric acid at the time. It was not until the invention of synthetic dyes a few decades later that the compound became commercially important. But even then, the lead chamber process was the preferred method for making sulfuric acid. Over time, improvements were made in the contact process, and it gradually became more and more popular. Today, nearly all of the sulfuric acid produced is manufactured by some modification of Peregrine Phillips method. 

Although the first benzimidazole was prepared by Hobrecker in 1872, it was Ladenburg who extensively explored the preparation of benzimidazole derivatives by the condensation between ort/to-amino aniline and carbonyl compounds (aldehydes and ketones) in 1875. Subsequently, Phillips further extended Ladenburg s preparation to the condensation between ort/io-amino aniline and acetic acid to produce different kinds of carboxylic acids in the presence of dilute mineral acid. Therefore, the preparation of benzimidazole from ort/io-amino aniline is referred to as the Ladenburg method," Phillips method, Phillips modification, or the Phillips-Ladenburg reaction. It has been proposed that the condensation between ortho-dxaim aniline and carbonyl compounds involves the formation of a Schiff base intermediate," whereas the condensation between ort/io-amino aniline and acid proceeds via the A,lV -diacyl and monoacyl intermediated This condensation generally works for aliphatic acids and is feasible for aromatic acids if the condensations are carried out above 180°C in sealed reaction vessels. ... 

The copolymerization of ethylene and 5% butene-1 or hexene-1 by the Phillips method gives a product which is resistant to stress craze corrosion. Under standard test conditions, this resistance is increased with 190 to 2000 h. A block copolymer of propylene with a small ethylene content can replace rubber-modified, unbreakable poly(propylene). 

The fifth and final chapter, on Parallel Force Field Evaluation, takes account of the fact that the bulk of CPU time spent in MD simulations is required for evaluation of the force field. In the first paper, BOARD and his coworkers present a comparison of the performance of various parallel implementations of Ewald and multipole summations together with recommendations for their application. The second paper, by Phillips et AL., addresses the special problems associated with the design of parallel MD programs. Conflicting issues that shape the design of such codes are identified and the use of features such as multiple threads and message-driven execution is described. The final paper, by Okunbor Murty, compares three force decomposition techniques (the checkerboard partitioning method. 

Phillips, J. B. Classification of Analytical Methods, Anal. Chem. 1981, 53, 1463A-1470A. 

Fluorocarbons are made commercially also by the electrolysis of hydrocarbons in anhydrous hydrogen fluoride (Simons process) (14). Nickel anodes and nickel or steel cathodes are used. Special porous anodes improve the yields. This method is limited to starting materials that are appreciably soluble in hydrogen fluoride, and is most useflil for manufacturing perfluoroalkyl carboxyflc and sulfonic acids, and tertiary amines. For volatile materials with tittle solubility in hydrofluoric acid, a complementary method that uses porous carbon anodes and HF 2KF electrolyte (Phillips process) is useflil (14). 

Molecular Weight. PE mol wt (melt index) is usually controlled by reaction temperature or chain-transfer agents. Reaction temperature is the principal control method in polymerization processes with Phillips catalysts. On the other hand, special chemical agents for chain transfer are requited for... 

Tbe system may be used for homopolymers and for block copolymers. Some commercial SBS triblock thermoplastic rubbers and the closely related K-resins produced by Phillips are of this type. Anionic polymerisation methods are of current interest in the preparation of certain diene rubbers. 

Phillips, H. 1987. A Comparison of Standard Methods for the Determination of Maximum Experimental Safe Gap (MESG). Proc. International Symposium on the Explosion Hazard Classification of Vapors, Gases, and Dusts, pp. 83-108. Publication NMAB-447. National Materials Advisory Board, Washington, DC. 

W. D. Phillips (NIST, Gaithersburg) development of methods to cool and trap neutral atoms with laser light. 

J. B. Phillips and J. Beens, Comprehensive two-dimensional gas chromatography a hyphenated method with strong coupling between the two dimensions , J. Chromatogr. 856 331-347 (1999). 

Ref 2). This was followed by Will in 1906 (Ref 3), Silberrad and Phillips in 1908 (Ref 4), and Kast in 1911 (Ref 5). More recently (1938), Hopper of PicArsn (Ref 6) detd and described the expl properties of the following metallic picrates Ai, Cd, Cr, Cu, Fe+3, Fe+2, Na, Ni and Zn. In general,he prepd the salts as cryst hydrates from aq solns by methods outlined by Silberrad Phillips, and Kast. These were then dehydrated by heating at temps of 80 to 150°, depending on the ease with which the w of crystn could be driven off, to obtain the desired degree of hydration... 

We did not feel any of these methods would work reliably on a commercial scale at current densities in the range of 300 mA cm"2 or for commercial periods (at least 4000 hr). Rudge s work9,10 with porous carbon anodes was a very elegant solution to the problem (and formed the basis for the Phillips Electrochemical Fluorination process), but the high electrical resistance of the porous carbon limited it to small anodes at high current densities or lower current densities on large anodes. 

Phillips, G. R., and Eyring, E. M., Error Estimation Using the Sequential Simplex Method in Nonlinear Least Squares Data Analysis, Anal. Chem. 60, 1988, 738-741. 

Zamecnik P.C, Stephensen M.L., Proc. Natl Acad. Sci. USA 1978, 75, 280-284. Antisense technology Part A General methods, methods of delivery and RNA studies. In Phillips M.I. (Ed.), Methods in Enzymology Vol. 313. Academic Press San Diego, CA, 2000. 

Antisense technology Part B Applications. In Phillips M.I. (Ed.), Methods Enzymology Vol. 314. Academic Press ... 

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