Potassium sulfide, preparation

A solution is prepared by diluting 0.7850 L of 1.262 M potassium sulfide solution with water to a final volume of2.000 L. 

Dining attempted preparation of trimethyl orthoformate, addition of sodium to an inadequately cooled chloroform-methanol mixture caused a violent explosion. See Ethanol (or methanol), Potassium sulfide, above See Sodium methoxide, below... 

The method described is adapted from the procedures of Kym 3 and Engelhardt, Latschinoff, and Malyscheff.4 Thio-benzoic acid has been prepared by the reaction of benzoyl chloride with potassium sulfide,4 hydrogen sulfide in pyridine,6 6 and magnesium bromide hydrosulfide.7 It is formed from dibenzoyl disulfide with potassium hydrosulfide,4 potassium hydroxide,4 8 and ammonia.9 It is also formed from dibenzoyl sulfide, from phenyl benzoate, and from benzoic anhydride with alcoholic potassium hydrosulfide.4 It has been obtained from dibenzoyl sulfide and hydrogen sulfide,10 carbon oxysulfide and phenyl-magnesium bromide,11 12 dibenzyl disulfide and sodium ethoxide,13 benzyl chloride and sulfur in the presence of potassium hydroxide,14 and benzylthiosulfuric acid and alkali.18 16... 

Prepare 50 cc. of a 5 per cent solution of potassium hydroxide. Divide this into two equal parts saturate the one with hydrogen sulfide and add it to the other. This gives a solution of potassium sulfide. Place the solution in a small flask, add 2 cc. of carbon disulfide, and shake thoroughly for some time. After about 5 min., filter through a wet filter. The orange-red solution contains K2CS3 and is a very sensitive reagent toward nickel. Make tests especially in the presence of cobalt. 

Thiobenzophenone has been prepared by the action of thio-phosgene on benzene in the presence of aluminum chloride 1 by the action of phosphorus pentasulfide on benzophenone 2 by the action of alcoholic potassium sulfide on benzophenone dichloride 3 by treating benzophenone dichloride with an alcoholic solution of sodium hydrosulfide 4 and by the action of thioacetic acid on benzophenone dichloride.5... 

Furfuryl mercaptan cannot be prepared according to the classical method using furfuryl chloride and potassium sulfide.2 It has been prepared by reduction of 2-furfuryl disulfide, obtained from furfural and ammonium hydrosulfide.3 The mercaptan has also been obtained in 33% yield 2 by the reaction of furfuryl chloride with thiourea and subsequent decomposition of the intermediate S-2-furfurylisothiourea according to the general method described in Organic Syntheses.4 In the present method, which has been published previously, the use of the very unstable and difficultly available furfuryl halides is avoided.6... 

Concerning the composition of alkali polysulfide, the yield of thiolane 7 suffered none in utilizing alkali polysulfide prepared from hydrated sodium sulfide or lithium or potassium sulfide rather than anhydrous sodium sulfide. When the ratio of sulfur to hydrated sodium sulfide was 8 1 or greater, the thiolane 7 resulted whereas at a ratio of 4 1, or using commercial Na, several components containing both sulfur and carbon were detected in me solid proauct. 

The parent compound (5) may be prepared by heating o-xylylene dibromide (a,a -dibromo-o-xylene) with sodium or potassium sulfide, usually in aqueous ethanol (see Table I for references), or by reducing phthalic thioanhydride (Section VII, B) with aluminum hydride or diborane 20 the former procedure has been used to prepare a number of derivatives of 5 (Table I). Disodium o-xylylenedimercaptide (6) can be isolated from the reaction between o-xylylene dibromide and... 

Both anhydrous and hydrated sodium or potassium sulfide in ethanol have been used in the synthesis of thietanes. A common procedure is to use a solution of sodium or potassium hydroxide saturated with hydrogen sulfide. Liquid ammonia has been used as a solvent for the preparation of thietane (32%) from sodium sulfide and 1,3-dibromopropane. Phase-transfer catalysis has been used to good effect.A variation in which l,3-dichloro-3-methylbutane 3 is treated with aluminium chloride and hydrogen sulfide followed by aqueous sodium hydroxide gave 2,2-dimethylthietane 4 in 90% yield. An intermediate aluminium chloride-alkene complex, 5 or 6, was proposed. 

A -Alkyl(thiocarbamoyl)]pyrazines have also been obtained by heating the 2-(A -alkylcarbamoyl)pyrazine with phosphorus pentasulfide and potassium sulfide in xylene at 100° (1268) and 2-amino-3-carbamoyl-5,6-diphenylpyrazine refluxed with phosphorus pentasulfide in pyridine gave 2-amino-5,6-diphenyl-3-thiocarbamoylpyrazine and the 3-A -butyl(thiocarbamoyl) analogue was prepared similarly (455). 2-Amino-5-chloro-3-(C-imino-C-methylthiomethyl)pyrazine with hydrogen sulfide in pyridine gave 2-amino-5-chloro-3-thiocarbamoylpyrazine (1218). 

Benzoyl disulfide has been obtained by the reaction of benzoyl chloride with hydrogen sulfide, hydrogen disulfide, hydrogen trisulfide, potassium sulfide, sodium disulfide, lead sulfide, sodium hydrosulfite, sodium thiosulfate, sulfhydrylmagnesium bromide, and thiobenzamide. It is also formed by reaction of benzoic anhydride with hydrogen sulfide. The better preparative methods involve the oxidation of thiobenzoic add by means of air,hydrogen peroxide or sulfur monochloride, or of the sodium or potassium salt by means of air, - chlorine, iodine, copper sulfate, - potassium ferricyanide, - or ferric chloride. - ... 

A large number of 3-pyrazolin-5-thiones and a few 5-seleno analogs (Table XVIII) have been prepared. Almost all of these have been synthesized by reaction of the methochloride or methiodide of a 3- or 5-halogenated pyrazole with potassium hydrogen sulfide,844,984,986,988,992 potassium sulfide, sodium sulfide901 or potassium hydrogen selenide.986 This method of synthesis is illustrated in eq. 149 for a 5-halopyrazole. 

Table 3-2 and Figure 3-2 describe the health effects observed in humans and experimental animals associated with dose and duration of oral exposure to selenium and selenium compounds (i.e., elemental selenium dust, selenium dioxide dissolved in water [selenious acid], sodium selenate, sodium selenite, potassium selenate, and dietary selenium compounds, which include selenoamino acids). All doses for these compounds are expressed in terms of total selenium. Table 3-3 and Figure 3-3 describe health effects observed in laboratory animals following oral exposure to selenium sulfides (SeS2 and SeS) at varying doses and exposure durations. All doses for selenium sulfide compounds are expressed in terms of the compound, because selenium sulfide preparations often exist as a variable mixture of the mono-and disulfide forms, precluding accurate expression of the dose in terms of total selenium. 

The earliest preparation of the poly(alkylene sulfides) was by polycondensation of a divalent metal sulfide or bis-mercaptide with alkylene dihalides. Poly(ethylene sulfide) was first prepared in 1839 by Loewig and Weidmann [40] and the polymer was later studied by Crafts [41] and Meyer [42]. The latter polymer was prepared from ethylene dibromide and potassium sulfide as shown in Eq. (14). 

The common method for preparing CuNs is by reaction of a cuprous salt with sodium azide. Aqueous solution of cupric salt (sulfate) is reduced with potassium sulfide giving cuprous sulfide as precipitate which is then dissolved by addition of acetic acid. In the following step, sodium azide is added to the solution, precipitating CuNs [78,107]. 

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