Preparation of Raney Nickel Catalyst

4-benzyloxy-3,5-dimethoxy-phenylethylamine hydrochloride white crystals with a melting point of 163° C. which are easily soluble in water. Source Gesellschaft 1931 See Friedrich Bayer Company 1911 

The proper proportions of nickel, aluminum and silicon are either melted separately, or together, and if the former, poured together in a suitable vessel. If this procedure is to be used, great care should be exercised, as the alloy is formed in an exothermic reaction. 

The melt may be made in a graphite crucible in any desired type of furnace or fire, care being used to prevent contamination of the melt by impurities from the fire. 

After the melt has fused and been thoroughly commingled, it is allowed to cool and is then pulverized in any desired apparatus. 

In its ground form it is then subjected to the action of a solvent such as caustic soda, or the like, which will dissolve all of the alloyed material with the exception of the nickel. After this treatment the subnatent fluid is decanted and the residue, consisting of finely divided nickel thoroughly washed. 

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In one of the earlier communications (8) dealing with a preparation of Raney nickel catalyst, it was shown that this catalyst when mixed with... 

Raney nickel catalysts (1, 723). The usual preparation of Raney nickel catalysts W-2 and W-h requires a tedious washing process with distilled water to remove the last traces of salt. Wynberg ct a P report that demineralization can be accomplished readily with an ion-exchange resin (Amberlite IR 121), hydrogen form). The resulting catalysts are somewhat more active than those prepared by the Organic Syntheses procedures. 

Adkins H, Billica HR. The preparation of Raney nickel catalysts and their use under conditions comparable with those for platinum and palladium catalysts. J Am Chem Soc. 1948 70 695. 

This procedure is based on the method of Lindsay and Hauser as modified slightly by Osgerby and Pauson. N,N-dimethyl-aminomethylferrocene methiodide has also been prepared by heating formylferrocene with dimethylamine and hydrogen in the presence of Raney nickel catalyst to give dimethylamino-methylferrocene, which was quaternized with methyl iodide. ... 

A solution of 151 grams of 1-(3, 4 -dimethoxyphenyl)-2-propanone oxime in 200 cc of absolute ethanol is treated with 5 grams of Raney nickel catalyst and ammonia in an autoclave at about 25 atm of pressure and at 75 -100°C. The reduction is complete in about one-half hour and the reaction mixture is filtered and fractionated under reduced pressure to recover the a-methylhomoveratrylamine formed by the reduction. a-Methylhomoveratryl-amine thus prepared boiled at 163°-165°C at 18 mm pressure. 

Acknowledgments—-The authors take pleasure in thanking the Research Corporation for grants (to I.M.H.) supporting this work. Special thanks also are due to Messrs. Donald Worth and James R. Smith for performing some of the synthetic work and to Mr. Arthur Rosenthal for preparing the Raney nickel catalyst. 

To promote the activity and selectivity of Raney nickel catalysts, alloying of the starting Ni-Al alloy with metal was often used. For instance, Montgomery (ref. 4) prepared catalysts by activating ternary alloy powders of Al (58 wt %)-Ni (37-42 wt %) - M (0.5 wt %) where M = Co, Cr, Cu, Fe and Mo. All promoted catalysts tested were more active than the reference catalyst, in hydrogenation of butyronitrile. Molybdenum was the most effective promoter. With Cr or Ti, hydrogenation of isophtalonitrile on Raney nickel occurred at lower optimum temperature than with non activated nickel (ref. 5). It was shown that addition of Ti or Co to Raney nickel suppressed the formation of secondary amine (ref. 6). 

B) Preparation of m-Amino-a-Ethylhydrocinnamic Acid A mixture of 50 g of a-ethyl-m-nitrocinnamic acid, 9.1 g of sodium hydroxide, 600 cc of water and 5 teaspoons of Raney nickel catalyst is shaken at 32°C in an atmosphere of... 

In 1925 Murray Raney (la) was granted a patent covering a new method of preparation of a nickel catalyst. A pulverized nickel-silicon alloy was reacted with aqueous sodium hydroxide to produce a pyrophoric, brownish nickel residue with superior catalytic properties. Upon investigation of other alloys of nickel and alkali-soluble metals, it was found that the aluminum alloy could be made with ease (lb) and was easily pulverized. The catalyst which is prepared by the action of aqueous sodium hydroxide on this nickel-aluminum alloy is known as... 

The process used for the preparation of Raney nickel was originally described in a patent issued to Murray Raney in 1927. The catalyst is prepared from Raney alloy which is commercially available and which consists of approximately equal weights of nickel and aluminum. 

Del6pine and Horeau (21) and Reichstein and Gatzi (22) received good results using small amounts of Raney nickel catalyst prepared in amounts just sufficient for use. The procedures consumed very little time because of the small quantities concerned. The advantage of always working with freshly prepared catalyst is obvious. 

Certain amines are readily prepared by the reduction of aromatic, aryl aliphatic, and heterocyclic amines. For example, aniline is reduced to cyclohexylamine by high-pressure hydrogenation in the presence of Raney nickel catalyst or a cobalt oxide-calcium oxide catalyst. The reaction occurs at a temperature above 200°, where condensation of the primary amine also takes place, viz., 2CjHiiNHj — (CjHn),NH + NH,. If this side reaction is repressed by the presence of dicyclohexylamine at the start of the reaction, a 94% yield of cyclohexylamine is obtained. Hydrogenation of aryl aliphatic amines proceeds more readily, occurring at moderate temperatures and pressures over platinum catalyst in glacial acetic acid. Other reductions using this catalyst are best performed on the amines in the form of their hydrochlorides. ... 

Metal cations can also affect the activity of Raney nickel catalysts. The presence of three to ten per cent of chromium or molybdenum in the Raney nickel alloy results in a general increase in the activity of the catalyst prepared from this alloy. Activation of nickel catalysts has also been accomplished by treating them with aqueous solutions of chromium chloride. Another effective promoter for Raney nickel is platinum which increases the activity of this catalyst for the... 

A solution of appropriate salts can also be reduced in the liquid phase by the addition of an appropriate reducing agent. Sodium borohydride has been used but care must be taken to remove the boron from the catalyst, particularly for the mixed noble metals. This has been accomplished by adding a dilute borohydride solution to the mixed metal salt solution under rapid agitation followed by a thorough washing of the precipitated metal black with warm water.The use of hydrazine, formaldehyde or formic acid is preferred to borohydride since the byproducts of the reduction do not contaminate the catalyst. Another procedure is to use a ternary alloy and to leach out one component as in the preparation of Raney nickel and similar catalysts. 

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