Sodium nickel periodate

Methyl 4,6-0-benzylidene-3-deoxy-a-D-ribo-hexopyranoside (56) was benzoylated, debenzylidenated, and partially p-toluenesulfon-ylated to 57 this was converted into 58 by reaction with sodium iodide, followed by catalytic reduction. The methanesulfonate of 58 was converted into 59 by reaction with sodium azide in N,N-dimethylformamide, and 59 was converted into 4-azido-3,4,6-trideoxy-a-D-xylo-hexose (60) by acetolysis followed by alkaline hydrolysis. Reduction of 60 with borohydride in methanol afforded 61, which was converted into 62 by successive condensation with acetone, meth-anesulfonylation, and azide exchange. The 4,5-diazido-3,4,5,6-tetra-deoxy-l,2-0-isopropylidene-L-ara/uno-hexitol (62) was reduced with hydrogen in the presence of Raney nickel, the resultant diamine was treated with phosgene in the presence of sodium carbonate, and the product was hydrolyzed under acidic conditions to give 63. The overall yield of 63 from 56 was 4%. The next three reactions (with sodium periodate, the Wittig reaction, and catalytic reduction) were performed without characterization of the intermediate products, and gave (+)-dethiobiotin methyl ester indistinguishable from an authentic sample thereof prepared from (+)-biotin methyl ester. 

For the oxidation of unsubstituted 1-aminopyrazole, the highest yield (46%) of 1,2,3-triazine is obtained with sodium periodate, which also provides high yields (82-93%) for other triazines (89H1809). 1,2,3-Triazine can be obtained in 20% yield on oxidation of N-aminopyrazole with nickel peroxide or lead dioxide in methylene chloride in the presence of acetic or trifluoroacetic acid (85JOC5520, 85LA1732) however, these results are not always reproduceable [86JCS(P1 )1249], As side products, cis- and zra/i.s-isomers of N./V -azopyrazoles are often isolated in yields of 35-45%. 

In another system [118], a prochiral sulfide is chemically converted into an optically active sulfoxide with appreciable enantioselectivity (ee 80%) upon reaction on the surface of a clay-ehelate adduct, A-tris-(l,10-Phenanthroline) nickel(II)-montmorillonite. The sulfide is added to a mixture of methanol/water (3 2) and is absorbed by the adduct. Under these conditions, the oxidation is effective with sodium periodate at room temperature in excellent yield (range of 80-90%) (Table 1.6). 

Compared to normal subjeets, niekel absorption did not differ in niekel-sensitive individuals. In a study using excised human skin, only 0.23% of an applied dose of niekel ehloride permeated skin after 144 hours when the skin was not oeeluded, while 3.5% permeated oeeluded skin (Fullerton et al. 1986). Nickel(II) ions from a ehloride solution passed through the skin 50 times faster than nickel(II) ions from a sulfate solution (Fullerton et al. 1986). Applieation of niekel ehloride in a sodium lauiyl sulfate solution (0.25%, 2%, or 10%) to exeised human skin resulted in a dose-related increase in the penetration of niekel during a 48-hour period (Frankild et al. 1995). 

Electrolysis prior to substrate addition with 1 mA/cra by changing the polarity of the nickel net from anode to cathode (period 5-10 sec) in a 0.1 N nickel sulfate, 0.1 N sodium acetate, 0.005 N sodium hydroxide solution until 0.5 Cb/cm are consumed. 

Periodic table colored pencils 5 ml samples of 0.1 M Cu(N03)2, Fe(N03)3, Co(N03)2, Ni(N03)2 and Zn(N03)2 small samples of bromine, iodine, sulfur, carbon, copper, iron, cobalt, nickel, zinc, magnesium and calcium and 0.1M 5 ml samples of sodium chloride, NaCl, and potassium chloride, KC1 magnesium nitrate, Mg(N03)2, and calcium nitrate, Ca(N03)2. 

Tetrakis[phosphorus(III) chloride] nickel is a pale yellow crystalline solid at room temperature and becomes colorless on cooling to about — 30°. This compound is stable in air when dry and unreactive with water at room temperature for a period of several days. It reacts slowly in the cold with dilute acids and with concentrated sulfuric or hydrochloric acid, but reacts rapidly in hot acid solutions. The compound reacts rapidly with ammonium hydroxide but more slowly with sodium hydroxide.1 It is reported that no decomposition occurs below 120° when the solid is heated, but that at higher temperatures the solid is decomposed and phosphorus (III) chloride is liberated 1 however, decomposition at 80° has been observed. Tetrakis[phos-phorus(III) chloride] nickel appears to be nonvolatile. 

In a 2-1. beaker resting on a hot plate and equipped with a mechanical stirrer are placed 150 g. of sodium hydroxide (Note 1) dissolved in 800 ml. of water and 41.4 g. (0.3 mole) of furyl-acrylic acid.1 The stirrer is started, and to the warm solution (Note 2) 100 g. of Raney nickel-aluminum alloy is added, in small portions, over a period of 4 4.5 hours (Notes 3 and 4). During the addition of the alloy, the temperature of the mixture is kept at 60-70° and then is raised to approximately 95° where it is held for an additional 2-3 hours, with stirring. From time to time sufficient water is added to the reaction mixture to maintain approximately the original volume. The hot solution is filtered by decantation, and the nickel residue (Note 5) is washed with two 50-ml. portions of hot 2% sodium hydroxide solution. The combined filtrates and washings are cooled and then immediately added slowly (Note 6), with good stirring, to 800 ml. of concentrated hydrochloric acid (Note 7). The solution at this point... 

Polymer-protected bimetallic clusters were also formed using a modified polyol process. The modification included addition of other solvents and sodium hydroxide. In the synthesis of Co-Ni with average diameters between 150 and 500 nm, PVP and ethylene glycol were mixed with either cobalt or nickel acetate with PVP. The glycol and organic solvents were removed from solution by acetone or filtration. The PVP-covered particles were stable in air for extended periods of time (months). 

Approximately 0.3 g. of sample, accurately weighed, is added to 100 ml. of 5 % aqueous sodium hydroxide contained in a beaker. Three grams of the nickel-aluminum alloy is added in three or four portions over a period of 10 minutes. When the reaction has subsided, the mixture is heated on a steam bath for 1 hour and then filtered, the residue being carefully washed. An aliquot portion of the filtrate may now be analyzed for halogens by any standard procedure. Ethanol may be used to facilitate the reduction of alkali insoluble compounds. 

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