Reduction sodium polysulfide

Reduction, of 1,3-dini tro-4, 6-diamin o-benzene to 2,4,5-triaminonitro-benzene by sodium polysulfide, 40,97... 

Lithium aluminum hydride is a convenient reagent for reduction of nitro compounds, nitriles, amides, azides, and oximes to primary amines. Catalytic hydrogenation works also. Aromatic nitro compounds are reduced best by reaction of a metal and aqueous acid or with ammonium or sodium polysulfides (see Section 23-12B). Reduction of /V-substituted amides leads to secondary amines. 

Aromatic amines are prepared by the reduction of nitro compounds under acidic conditions this leads to the protection of the resultant amine as the salt. The selective reduction of one nitro group in 1,3-dinitrobenzene can be achieved with sodium polysulfide. 

A peculiar oxido-reductive reaction takes place when p-aminotoluene is heated with sodium polysulfide the product is p-aminobenzaldehyde [505]. 

In addition to the reduction of sodium sulfate, an electrolysis process is operated in which a sodium polysulfide solution (from sodium sulfide solution and... 

Important sulfur dyes are made by treating aryl amines with sodium polysulfides, or by heating the amines with sulfur, followed by treatment with sodium sulfide. Certain sulfur blacks are made from anilines that include p-aminophenol and p-phenylenediamine (22). Derivatives of diphenylamine (8) yield blue shades. Meta-diamines, such as m-phenylenediamine (52a), give brown and yellow colorants. Sulfur dyes are inexpensive, but lack brilliance. There are no red members of this class. They are applied by means of reduction and oxidation processes. 

Dunbrook and Zimmermann 113) report still higher yields, even with short reaction times, when sodium polysulfide and carbon disulfide are used (method C ). The essential appears to be the replacement of the chlorine atom by a mercapto group and the reduction of the nitro group to an amino group, followed by ring closure of the resulting o-aminothiophenol with carbon disulfide to the benzothiazoline-2-thione (method A). 

Pyrazine- and quinoxalinethiones have been synthesized by treatment of halogeno compounds with sodium or potassium hydrogen sulfide, sodium polysulfide, phosphorus pentasulfide, or thiourea . Pyrazinethiones are directly prepared by treating 2(177)-pyrazinones with Lawesson s reagent (2,4-bis(4-methoxyphenyl)-l,3,2,4-dithiadiphosphetane 2,4-disulfide) <83H(20)797>. They are also obtained by treatment of (4-methoxybenzylthio)pyrazines with mer-cury(II) acetate and successive reduction <93JCS(P1)15>. 

The sulfur-sodium polysulfide system has received the attention of electrochemists but few of the studies have been under conditions comparable to sodium-sulfur battery operating conditions. The thermodynamics of the system have been studied by means of open-circuit potentials (17,27), and dynamic measurements have been made in fused salts (28). The most pertinent studies are those of sulfur-polysulfide electrochemistry in the actual sulfur-polysulfide melts (24, 29, 35). The results of these studies seem to indicate that both the oxidation and reduction reactions are rapid, although the oxidation reaction is hindered by the formation of an insulating sulfur film. These studies also concluded that the electrode reaction sequences were quite complex because of the multitude of polysufide species. As the system becomes better characterized more quantitative descriptions are possible as evidenced by a recent work which modeled the resistive drop through an actual sulfur impregnated graphite electrode in order to correlate the spatial distribu-... 

The method of sulfide reductions, although more expensive than iron and acid or catalytic reduction, has a wide field of application, particularly with respect to partial reductions and reductions in the anthraquinone series. Sodium sulfide, sodium hydrosulfide (the sulfhydrate of commerce), sodium polysulfides, ammonium sulfide, etc., are employed. Quite a number of benzene derivatives are normally reduced by this general method, and it is noteworthy that the first reduction of nitrobenzene was that by Zinin in 1842, using ammonium hydrosulfide. Where the presence of free... 

Sulfide reduction employs sodium sulfide, sodium polysulfide, or sodium hydrosulfide. An important feature of this type of reducing system is its adaptability to bring about stepwise reduction of dinitro compounds. Partial reduction is illustrated with m-dinitro-benzene, which can be reduced to m-nitro-aniline with sodium sulfide under controlled conditions ... 

Zinin Reduction. The method of reducing aromatic nitro compounds with divalent sulfur is known as the Zinin reduction (57). This reaction can be carried out in a basic media using sulfides, polysulfides, or hydrosulfides as the reducing agent. These reactions can be represented as follows when the counter ion is sodium ... 

As evaporation proceeded, sodium chloride began to precipitate and later potassium chloride and potassium sulfate. The mother liquor then contained the iodides of sodium and postassium, part of the sodium chloride, sodium sulfate, sodium carbonate, cyanides, polysulfides, and some sulfites and hyposulfites resulting from the reduction of sulfates during calcination. 

Diethyl mercaptoacetal has been prepared by treating diethyl bromoacetal with potassium hydrosulfide 3 by the reduction of 1,1,11 -tetraethoxyethyl disulfide 3 with lithium aluminum hydride by reduction of 1,1-diethoxyethyl benzyl sulfide,3 41,1,1/,1/-tetraethoxyethyl disulfide,3 and 1,1,1, 1 -tetracthoxyethyl polysulfide 3 with sodium and liquid ammonia. The method described is adapted from the last-named preparation. Dimethyl mercaptoacetal has been prepared by the same methods.3... 

Phenylacetamide has been obtained by a wide variety of reactions from benzyl cyanide with water at 250-260° 6 from benzyl cyanide with water and cadmium oxide at 240° 6 from benzyl cyanide with sulfuric acid 7 8 by saturation of an acetone solution of benzyl cyanide with potassium hydrosulfide 9 from benzyl cyanide with sodium peroxide 10 by electrolytic reduction of benzyl cyanide in sodium hydroxide 11 from ethyl phenyl-acetate with alcoholic 12 or aqueous 13 ammonia from phenyl-acetic acid with ammonium acetate 14 or urea 15 from diazoacetophenone with ammoniacal silver solution 16 from phenyl-acetic acid imino ether hydrochloride and water 17 from acetophenone with ammonium polysulfide at 215° 18 from benzoic acid 19 and by heating the ammonium salt of phenyl-acetic acid.20... 

Amino-4-nitrophenol is produced commercially by the partial reduction of 2,4-dinitrophenol. This reduction may be achieved electrolyticaUy using vanadium (159) or chemically with polysulfide, sodium hydrosulfide, or hydrazine and copper (160). Alternatively, 2-acetamidophenol or 2-methylbenzoxazole may be nitrated in sulfuric acid to yield a mixture of 4- and 5-nitro derivatives that are then separated and hydrolyzed with sodium hydroxide (161). 

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