Sodium sulfide nitro amines

Sulfur Dyes. These dyes arc synthesized by heating aromatic amines, phenols, or nitro compounds with sulfur or. more usually, alkali polysullides. Sulfur dyes are used for dyeing cellulosic fibers. They are insoluble in water and are reduced to ihe water-soluble leuco form for application to the substrate by using sodium sulfide solulion, The sulfur dye proper is then formed within the fiber pores by atmospheric oxidation. Sulfur dyes constitule an important class of dye lor producing cost-effective tertiary shades, especially black, on cellulosic fibers. 

Anion-exchange resins have also been prepared through the nitration of SDVB copolymers with sulfuric acid-nitric acid mixture followed by the reduction of nitro groups with sodium sulfide . Such resins containing —NHj groups have been further modified with ethylenimine or hydroxylamine Aminated polystyrene can be crosslinked with dichloroethane to give an anion-exchange resin... 

Partial reduction of aromatic polynitro compounds leads to nitro amines. The most successful reagents are the alkali metal or ammonium sulfides in aqueous alcoholIn some instances, sodium bicarbonate combined with sodium sulfide gives better results because of the formation of sodium hydrosulfide, which is believed to be the main reducing agent. Also, aqueous methanol is preferred to aqueous ethanol. Nitro compounds that are sparingly soluble in alcohol solutions may be reduced by hydrogen sulfide in pyridine solution. ... 

To a hot solution of 12.1 g. (0.05 mole) of 3 nitro-4-methylbenzo-phenone (p. 228) in 300 ml. of ethanol is added dropwise a hot solution of 22.5 g. of crystalline sodium sulfide in 30 ml. of ethanol and 30 ml. of water. The reaction mixture is poured into 500 ml. of water, and the precipitated oil solidifies on cooling. The solid product is suspended in 600 ml. of boiling water and treated with concentrated hydrochloric acid until no more solid dissolves. The mixture is filtered rapidly, and the filtrate is treated with excess aqueous ammonia. The precipitated solid is recrystallized from methanol to give 9 g. (85%) of amine, m.p. 109-110°. 

Manufacture of many important amino intermediates used for dyes and other purposes is usually by conversion or replacement of a substituent. For example, as already mentioned, in substituted nitro compounds, the nitro groups may be reduced with iron/hydrochloric acid, hydrogen and catalyst, or zinc in aqueous alkali. Partial reductions can be brought about with sodium sulfide. Amino groups may be introduced by replacing halogens in the aromatic ring. Another approach to amination is by attack on a substituted aromatic compound with ammonia or amines. Thus, for example, direct amination of p-chloronitrobenzene (15a) in the presence of a copper catalyst affords p-nitroaniline (15b) in almost quantitative yield l,4-dichloro-2-nitrobenzene (16) is converted in a similar way to 4-chloro-2-nitroaniline (17). Reactions of ammonia with carboxylic acids or anhydrides are carried out on an industrial scale. 

The reduction of carbazole nitro groups to the primary amines is straightforward stannous chloride, tin-hydrochloric acid, iron-hydrochloric acid" hydrogen-palladium/charcoal," hydrogen-nickel,hydrazine-palladium,and hydrazine-nickeP have all been employed. 3,6-Dichloro-l,8-dinitrocarbazole was partially reduced with sodium hydrogen sulfide to give l-amino-8-nitro-3,6-dichloro-carbazole. ... 

Applications The Karl Fischer reagent can be applied directly to the determination of water in a variety of organic compoimds, including saturated or unsaturated hydrocarbons, alcohols, halides, acids, acid anhydrides, esters, ethers, amines, amides, nitroso and nitro compounds, sulfides, hydroperoxides, and dialkyl peroxides. The use of sodium tartrate dihydrate for standardization of the response of the Karl Fischer reagent has been shown to lead to a small error because of occlusion of about 2% (relative) water in the crystal structure. 

Sodium perborate, NaBOa dlljO (mp 60 °C dec), is used for oxidations of primary aromatic amines to azo compounds [795] or nitro compounds [194] and of sulfides to sulfoxides and sulfones [794]. This reagent does not affect alcohols and only slightly affects alkenes [794]. 

According to Teppema and Sebrell [357], the preparation of benzo-thiazoline-2-thiones from aryl amines, sulfur and carbon disulfide is not generally applicable. This has been confirmed by several other authors. Another synthesis, method C, has been worked out starting with o-nitro chloro benzenes. On warming these products in a solution of sodium hydrogen sulfide with slow addition of hydrogen sulfide in the presence of carbon disulfide, near 90% yields of benzothiazoline-2-thiones are obtained. 

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