Alkaline reduction

The alkaline reduction of an aromatic nitro-compound to give the azoxy... 

Fig. 1. After dia2o coupling, oxidation leads tria2ene ring formation. Alkaline reduction and coupling lead to (9).

Alkalinity Reduction. Treatment by lime precipitation reduces alkalinity. However, if the raw water alkalinity exceeds the total hardness, sodium bicarbonate alkalinity is present. In such cases, it is usually necessary to reduce treated water alkalinity in order to reduce condensate system corrosion or permit increased cycles of concentration. 

The heptamethylene glycol was separated by continuous ether extraction from the alkaline reduction solution after the latter had been diluted and distilled to remove the alcohol. The nonamethylene glycol was separated from the alkaline liquor by decantation (as above) and distilled. All the others were crystallized from benzene (without alcohol). Equally successful results have also been obtained with larger runs (e.g., 0.5 mole of ester),... 

A further anomaly in nomenclature is thebainol, the name applied to the substance formed by the alkaline reduction of metethebainone, and which was at first believed to be formed by reduction of the carbonyl group, but which Gulland and Robinson proved to be a ketone. It is isomeric with dihydrothebainone referred to above, and has been re-named dihydrom tathebainone (Schopf). The interrelationships of these substances are shown by the following formulae —... 

The HO—LU interaction came early to the notice of theoreticians. Hiickel 74> pointed out the role of LU in the alkaline reduction of naphthalene and anthracene. Moffitt 75> characterized the formation of S03, SO2CI2, etc. by the reactions of SO2 as an electron donor with the S-atom-localiz-ing character of HO MO. Walsh 76) considered that the empirical result of producing nitro compounds in the reaction of the nitrite anion with the carbonium ion should be attributed to the HO of the NO2 anion which is localized at the nitrogen atom. 

The stripping of cellulosic materials dyed with reactive dyes is carried out by alkaline reduction followed by hypochlorite oxidation, preceded by a boiling treatment with EDTA if metal-containing dyes have been used. For example, a treatment with 5 gA sodium carbonate or sodium hydroxide and 5g/l sodium dithionite at the boil is followed by a treatment in 0.5-1 °Tw hypochlorite, an antichlor and thorough rinsing. 

The procedure described is essentially that of Ballard and Dehn.1 Stilbene has also been prepared by reduction of desoxy-benzoin,20 benzaldehyde,23 and benzil 2o-2c by dehydrogenation of ethyl benzene,30 toluene,30- 33- 3, and bibenzyl 33-3benzyl sulfone,50 benzyl sulfide,60-63 calcium cinnamate,5 cinnamic acid,5d phenyl cinna-mate,6e-6/ and diphenyl fumarate ie by dehydrohalogenation of a,a -dichlorobibenzyl60 and benzyl chloride 63 by dehalogenation of a,a,c/,a -tetrachlorobibenzyl70 and benzal chloride 73 by the coupling of cinnamic acid and phenyldiazonium chloride 8 by de-... 

Diaminodiphenyl derivatives can be obtained from appropriately substituted nitrobenzenes by a rather dated process of alkaline reduction with zinc powder/ sodium hydroxide solution, which affords hydrazobenzene. A more recent method uses a catalytic reduction process with hydrogen and specifically deactivated catalysts of precious metals. Subsequent acid-catalyzed rearrangement with hydrochloric acid yields the hydrochloride of the target diamine ... 

Alkaline reduction of o-nitro-anisole leads (as in the case of nitrobenzene) to the hydrazo-compound, which undergoes a benzidine trans-... 

The purported existence of the [V(CN)5NO] ion has been questioned. The electrode potentials relevant to the only preparative method described for this ion, the alkaline reduction of metavanadate by hydroxylamine in the presence of excess cyanide, suggest that no reaction should occur. This seems to be correct,... 

Platinum carbonylate anion clusters like [Pt3(CO)6] can be obtained by alkaline reduction of [PtCh] in a CO atmosphere. From [Pt3(CO)s] other higher nuclear-ity anions can be obtained. In this context, several examples have been reported in which this type of anionic cluster is used in the preparation of catalysts by impregnation or exchange methods. Salts of [Pt3 (CO)6 ] (n = 3, 5) have been used to prepare, by impregnation, dispersed platinum on ZnO and MgO [49] and, by ion exchange methods, to prepare Pt3 /C electrodes for the electrocatalytic oxidation of methanol [50]. A salt of [Pti2(CO)24] has recently been used to prepare... 

Identification of azoxy compds) CA 45, 57K195D 10)H.W.Galbraith et al. JACS 73, 1323-4(1951) (Alkaline reduction of aromatic nitro compds with glucose to azoxy compds)... 

This side reaction cannot be avoided when reducing aliphatic ketones, but in the aromatic series either product can be obtained by varying the conditions of the reduction. An alkaline reduction favours alcohol production pinacones are formed when acid reducing agents are employed (see Preparation 16). 

The reaction is really an extension of that on alkaline reduction, since the solution of sodium sulphide in water is alkaline. The complete equations are ... 

After the dyes are fixed, dyes and auxiliaries that adhere superficially must be washed out, if necessary, by an alkaline reductive treatment. In the case of PES-CEL fiber blends, this washing can be combined conveniendy with afterdyeing of the cellulose component, e.g., simply by overdyeing with vat dyes (see Section 4.4.3). For details of the thermosol process, see [85, pp. 122-131],... 

The influence of the cathode metal is much more manifest when acid electrolytes are employed than in alkaline reduction. In alkaline solution at copper electrodes, if we except the last-mentioned process, the rapidly occurring condensation of the first reduction phases—of the nitroso- and hydroxylamine body—always leads immediately to the azoxy-body and makes this appear to be the typical product of the alkaline reduction, which can in turn be further reduced. In acid solution this condensation takes place so slowly that the molecular rearrangement of the hydroxylamine and its further reduction to amine has time to take place alongside the formation of the azoxy-body and the reduction of the latter to the hydrozo-compound or benzidine.4... 

Several representatives of this ( lass of compounds wore investigated as to their behavior in alkaline reduction (Hans-STiuatm and Schmidt l). These investigators continued ilio rules which Klb established for nitrophenyl ethers. 

Kohde has investigated the influence of methyl groups in f he iimidfegroiips in alkaline reduction. 

Phenyl-p-tolylketone, by alkaline reduction, gives almost quantitatively phenyl-p-tolylcarbinol ... 

Phenyl-m-xylylket one.—The reaction product of the alkaline reduction is a liquid modification of phenyl-m-xylylcarbinol but in sulphuric-acid-acetone solution at the boiling temperature phenyl-m-xylylpinacone is obtained. The yield of the latter is 40-50 per cent, of that theoretically possible. 

Number of Carbohydrate and Selected Amino Acid Residues per Mole of Glucoamylase before and after Alkaline Reductive /3-Elimination Reaction... 

The product from (b) is dissolved in 1 liter water and treated with 50 grams of concentrated sulfuric acid, previously somewhat diluted. 40 grams of flowers of sulfur is added and the mixture is stirred for 3 hours at 95°C., adding water from time to time. The resulting dye is allowed to settle, and is then filtered off, washed with water, and iried at about 80°. The yield of thioindigo is about 25 grams, or 70 per cent of the theoretical amount based on the O acid. The product contains some sulfur and can be purified by alkaline reduction and reoxidation. 

The hydrol can also be prepared, although less satisfactorily, by alkaline reduction of Michler s ketone. The hydroxyl group in the hydrol is extremely reactive it is alkylated, for example, merely by boiling with alcohol. The technical importance of the hydrol arises from the ease with which it condenses with various aromatic compounds to form leuco compounds of triphenylmethane dyes (see wool green S, page 307). 

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