Stephens

STEPHEN,H, STEPHEN,T E0S /S0LUBIL1TIES OF INORGANIC MO ORGANIC COMPOUNDS,MACMILLAN CO, NEW YaRK(1964) ... 

Stephen, H., Stephen, T., "Solubilities of Inorganic and Organic Compounds," Pergamon Press, New York (1963). 

Stephen Gould s writing is elegant, erudite, witty, coherent and forceful - Richard Dawkins, Nature... 

Work expands so as to fill the time available for its completion that law underlies this extraordinarily tunny and witty book (Stephen Potter in the Sunday Times) which also makes some painfully serious points for those in business or the Civil Service. 

BE-1426 Structural integrity assessment procedures for European industry Mr. E. Stephen Wabiter British Steel PLC... 

George R Darling, Stephen Holloway and Charles Rettner... 

Figure Bl.26.1. Sorption isothemi for chemisorption of hydrogen on palladium film at 273 K (Stephens S J 19597. Phys. Chem.. 63 188-94).

Stephens P W, Mihaly L, Lee P L, Whetten R L, Huang S-M, Kaner R, Diederioh F and Holozer K 1991 Struoture of single phase superoonduoting K,Cgg Nature 351 632... 

Stephens P W, Bortei G, Faigei G, Tegze M, Janossy A, Pekker S, Oszianyi G and Forro L 1994 Poiymerio... 

Kurst G R, R A Stephens and R W Phippen 1990. Computer Simulation Studies of Anisotropic iystems XIX. Mesophases Formed by the Gay-Berne Model Mesogen. Liquid Crystals 8 451-464. e F J, F Has and M Orozco 1990. Comparative Study of the Molecular Electrostatic Potential Ibtained from Different Wavefunctions - Reliability of the Semi-Empirical MNDO Wavefunction. oumal of Computational Chemistry 11 416-430. 

From nitriles by treatment with anhydrous Stannous chloride dissolved in ether saturated with hydrogen chloride the resulting crystaUine aldimine stannichloride, [(RCH=NHj)2] SnCl, or (RCH=NH,HCl)2SnCl4, is hydrolysed by warm water, and the aldehyde is isolated by distillation with steam or by extraction with a solvent (Stephen reaction), for example, for R = CH3(CH2)4, i.e., n-amyl ... 

From nitriles by Stephen s reaction (see under Aliphatic Aldehydes and Section 111,64), for example ... 

Stephen reaction Stobbe condensation UUmann reaction Willgerodt reaction. ... 

John von Neuman, one of the greatest mathematicians of the twentieth century, believed that the sciences, in essence, do not try to explain, they hardly even try to interpret they mainly make models. By a model he meant a mathematical construct that, with the addition of certain verbal interpretations, describes observed phenomena. The justification of such a mathematical construct is solely and precisely that it is expected to work. Stephen Hawking also believes that physical theories are just mathematical models we construct and that it is meaningless to ask whether they correspond to reality, just as it is to ask whether they predict observations. 

The Stephen s method allows the reduction of nitriles by stannous chloride in acid medium. If the amine chlorhydrate initially formed is hydrolyzed, the corresponding aldehyde is obtained (37, 91). Harington and Moggridge (37) have reduced 4-methyl-5-cyanothiazole by this method (Scheme 23). However, Robba and Le Guen (91) did not obtain the expected products with 4.5-dicyanothiazole and 2-methyl-4,5-dicyanothiazole. These compounds have been reduced with diisobutyl-aluminium hydride with very low yields (3 to 6%) (Scheme 24). In other conditions the reaction gives a thiazole nitrile aldehyde with the same yield as that of the dialdehyde. 

As mentioned previously, aldehydes can be prepared by Stephen s method of reduction of nitriles by stannous chloride (37, 91). Polaro-graphic reduction of thiazolecarboxylic acids and their derivatives gives lower yields of aldehydes (58). Ozonolysis of styrylthiazoles, for example, 2-styryl-4-methylthiazole, followed by catalytic reduction gives aldehyde with 47% yield of crude product (30). 

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