Zinc hydride hydroxide

Bis(2-nitrophenyl)amine (la) is reduced by zinc/ sodium hydroxide to a mixture of 117/-dibenzo[r, /][l,2,5 triazcpine (2a) and the V-oxidc 3a.325 The reaction of Ar-methylbis(2-ni-trophenyl)amine with lithium aluminum hydride provides 11-methyl-1 l//-dibenzo[c,/][l,2,5]tri-azepine (2b).153... 

For the polymerization to proceed at a reasonable rate, the use of a transesterification catalyst is needed. Compounds which are usually used as a catalyst for the preparation of polyesters through transesterification can be used here. These include lithium, sodium, zinc, magnesium, calcium, titanium, maganese, cobalt, tin, antimony, etc. in the form of a hydride, hydroxide, oxide, halide, alcoholate, or phenolate or in the form of salts of organic or mineral acids, complex salts, or mixed salts.(10) In this study, tetrabutyl titanate (TBT) in the amount of 1000 ppm was used normally. 

Sodium hydride s. under (MeCOO)2Ni Zinc sodium hydroxide... 

A number of basic materials such as hydroxides, hydrides and amides of alkaline and alkaline earth metals and metal oxides such as zinc oxide and antimony oxide are useful catalysts for the reaction. Acid ester-exchange catalysts such as boric acid, p-toluene sulphonic acid and zinc chloride are less... 

Industrially, chlorine is obtained as a by-product in the electrolytic conversion of salt to sodium hydroxide. Hazardous reactions have occuned between chlorine and a variety of chemicals including acetylene, alcohols, aluminium, ammonia, benzene, carbon disulphide, diethyl ether, diethyl zinc, fluorine, hydrocarbons, hydrogen, ferric chloride, metal hydrides, non-metals such as boron and phosphorus, rubber, and steel. 

Hydrogen can be prepared by the reaction of water or dilute acids on electropositive metals such as the alkali metals, alkaline earth metals, the metals of Groups 3, 4 and the lanthanoids. The reaction can be explosively violent. Convenient laboratory methods employ sodium amalgam or calcium with water, or zinc with hydrochloric acid. The reaction of aluminium or ferrosilicon with aqueous sodium hydroxide has also been used. For small-scale preparations the hydrolysis of metal hydrides is convenient, and this generates twice the amount of hydrogen as contained in the hydride, e.g. ... 

The dibenzoxadiazepine 1 is converted into 5.6-dihydrodibenz[/>,/][l,4,5]oxadiazepine (3) by treatment with hydrazine in the presence of Raney nickel153 or with lithium aluminum hydride or with zinc and sodium hydroxide.325 The product reverts to the starting material by the action of mercury(II) oxide153 or on exposure to air.325... 

In acidic electrolytes only lead, because it forms passive layers on the active surfaces, has proven sufficiently chemically stable to produce durable storage batteries. In contrast, in alkaline medium there are several substances basically suitable as electrode materials nickel hydroxide, silver oxide, and manganese dioxide as positive active materials may be combined with zinc, cadmium, iron, or metal hydrides. In each case potassium hydroxide is the electrolyte, at a concentration — depending on battery systems and application — in the range of 1.15 - 1,45 gem"3. Several elec-... 

Results of reductions of cyclic anhydrides to lactones with sodium amalgam or with zinc are inferior to those achieved by complex hydrides [1020]. However, 95.6% yield of phthalide was obtained by reduction of phthalimide with zinc in sodium hydroxide [1021]. 

A large variety of reducing agents have been proposed for this reduction. However, zinc and sodium hydroxide offer the most common system, and lithium aluminum hydride merits consideration. The reduction of azoxy compounds with lithium aluminum hydride has value mainly in structural determinations. Its importance as a preparative procedure is limited normally such a reaction sequence would be a matter of putting the cart before the horse. The reduction of azines has potential value because of the accessibility of azines unfortunately, only under specialized circumstances has it been possible simply to add the required gram-molecule of hydrogen to the structure. Usua-ally, chlorine is added to an azine structure to produce dichloro azo compounds. An extension of the reaction permits the preparation of a,a -diacyl-oxyazoalkanes from azines. 

From the standpoint of laboratory-scale preparations, probably the most commonly used method is the reduction with zinc in a sodium hydroxide medium. The use of lithium aluminum hydride also merits consideration. 

This reaction does not proceed in carbon tetrachloride solution.10 Retgers 11 stated that the solid hydride resulted when arsine was heated or when the flame of arsine impinged on a cold plate but other observers 12 maintain that arsenic alone is produced. A solid hydrogen-containing product has also been obtained by the action of zinc, in the presence of sulphuric and nitric acids, on arsenious oxide,13 and by the action of arsine on solid potassium hydroxide,14 followed by the addition of water. A good yield (up to 98 per cent.) of the hydride in a comparatively pure state may be obtained by mixing an ether solution of stannous chloride with a solution of arsenic trichloride in dilute hydrochloric acid.15 The reaction is ... 

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