Sodium sulfide hydrate

Much information on the process to prepare PPS from 1,4-dichlorobenzene and sodium sulfide is proprietary and the process is not as easy as it looks. Sodium sulfide hydrate or a mixture of aqueous sodium hydrosulfide and sodium hydroxide is dissolved in a polar organic solvent such as N-methylpyrrolidone and the system dehydrated. Then 1,4-dichlorobenzene is added and the system held at 200 to 300 C until pol)niierization is complete, usually within ten hours. Two moles of sodium chloride are formed for every mole of PPS, and the weight of sodium chloride formed is greater than the theoretical yield of... 

Sodium Hydrogen Sulfate Solution 2837 60 Sodium Sulfide, hydrated, with not 1849 60... 

MIXED ACID, spent 1849 60 SODIUM SULFIDE, hydrated with not less than 30% water... 

Poly(phenylene sulfide) (PPS) is an important engineering thermoplastic which is produced by the polymerization of sodium sulfide-hydrate and p-dichlorobenzene at 200 - 280 C in NMP (24) (Scheme V). The classical synthesis, characterization and properties of PPS has been reviewed (25). In recent years, research on the mechanism of PPS formation, and several new routes to PPS have been reported and will be surveyed here. 

Proposals for the mechanism of PPS formation include nucleophilic aromatic substitution (Sj Ar) (2radical-cation (27), and radical-anion processes (28,29). Some of the interesting features of the polymerization are that the initial reaction of the sodium sulfide-hydrate with NMP affords a soluble NaSH-sodium 4-(N-methylamino)butanoate mixture, and that polymers of higher molecular weight than pi edicted by the Caruthers equation are produced at low conversions. Mechanistic elucidation has been hampered by the harsh polymerization conditions and poor solubility of PPS in common organic solvents. A detailed mechanistic study of model compounds by Fahey provided strong evidence that the ionic S]s Ar mechanism predominates (30). Some of the evidence supporting the S s(Ar mechanism was the selective formation of phenylthiobenzenes, absence of disulfide production, kinetics behavior, the lack of influence of radical initiators and inhibitors, relative rate Hammet values, and activation parameters consistent with nucleophilic aromatic substitution. The radical-anion process was not completely discounted and may be a minor competing mechanism. 

Vinyl chloride reacts with sulfides, thiols, alcohols, and oximes in basic media. Reaction with hydrated sodium sulfide [1313-82-2] in a mixture of dimethyl sulfoxide [67-68-5] (DMSO) and potassium hydroxide [1310-58-3], KOH, yields divinyl sulfide [627-51-0] and sulfur-containing heterocycles (27). Various vinyl sulfides can be obtained by reacting vinyl chloride with thiols in the presence of base (28). Vinyl ethers are produced in similar fashion, from the reaction of vinyl chloride with alcohols in the presence of a strong base (29,30). A variety of pyrroles and indoles have also been prepared by reacting vinyl chloride with different ketoximes or oximes in a mixture of DMSO and KOH (31). 

Treatment of nitriles with gaseous hydrogen sulfide in the presence of anion exchange resin (Dowex 1X8, SH from) at room temperature affords the corresponding primary thioamides.27 Treatment of nitriles with 70% sodium hydrosulfide hydrate and magnesium chloride hexahydrate in DMF or methanol affords primary thioamides in high yields.28 Primary thioamides have been... 

Having pyrazinylacetylenes in hand, one could convert the alkynyne functionality into the corresponding ketone via hydration [33], Thus, the coupling of iodide 36 and acetylene 37 produced pyrazinylalkyne 38. Subsequent exposure of 38 to aqueous sodium sulfide and aqueous hydrochloric acid in methanol led to ketone 39. Such a maneuver provides additional opportunities for further manipulation of the alkynes derived from the Sonogashira coupling reactions. 

Eighty grams of sodium sulfide 9-hydrate are melted in a suitable evaporating dish over a small flame. Under constant stirring, 8g of powdered phosphorus pentasulflde are... 

One milliliter of a saturated aqueous solution of mercuric chloride is treated dropwise with a saturated solution of sodium sulfide 9-hydrate in water until complete solution has taken place ... 

To obtain 2,5-bis(benzoxazol-2-yl)thiophene (39), two equivalents of 2-chloro-methylbenzoxazole are treated with sodium sulfide and the thiophene ring is formed with glyoxal hydrate [70] ... 

The combination of radiolabeled sulfide and the bimane-HPLC method is particularly powerful because one of the main obstacles to the use of labeled sulfide is, that aside from radioactive decay, the compound is subject to rapid oxidation in the presence of air. The breakdown products of chemical sulfide oxidation are the same as those of biological oxidation. Previously it has been impossible to check routinely the purity of the purchased isotope and its subsequent purity during a series of experiments. It is our experience that newly purchased sodium sulfide sometimes contains up to 10% thiosulfate as well as traces of sulfite and sulfate (Figure 2), and that the sulfide once hydrated readily oxidizes if stored in a normal refrigerator. 

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. 

Commonly employed reducing agents are sodium borohydride, sodium sulfide nonahy-drate, potassium sulfide, sodium or potassium hydrogen sulfite (Vol. IX, p. 1068), sodium disulfite, hydrazine hydrate, and thiourea dioxide. Lithium diethylamide1 has been found to reduce diaryl tellurium dichlorides. Methyl magnesium iodide is recommended in the older literature as a reducing agent (Vol. IX, p. 1069). 

Merck s reagent grade of sodium sulfide nonahydrate was used. Since sodium sulfide decomposes on contact with air, a freshly opened bottle should be employed. Sodium Sulfhy-drate (Hooker Electrochemical Company hydrated sodium hydrosulfide) is also satisfactory the amount should be based upon the formula NaHS 2H20, and an equivalent amount of sodium hydroxide in excess of the 27 g. is required. 

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. 

Aryl tellurium halides are easily reduced to diaryl ditellurium compounds by sodium sulfide, sodium disulfite , zinc in refluxing toluene, or hydrazine hydrate (p. 273). 

Aryl tellurium trihalides are easily reduced by sodium hydrogen sulfite , sodium or potassium disulfitezinc in refluxing ethanoP, hydrazine hydrate " hypophos-phorous acid °, sodium sulfide nonahydrate , sodium borohydride , thiourea diox-ide, 4-methylbenzenesulfonyl hydrazide , or diphenylsilane. The reductions with sulfites are generally carried out in an aqueous medium in the presence of an immiscible organic solvent that extracts the ditellurium. 

Phenothiatellurin 10,10-dichloride was quantitatively reduced by sodium sulfide nona-hydrate or by aqueous potassium disulfite to phenothiatellurin, a yellow, crystalline solid with a melting point of 123° (ethanol). 

Further evidence of specific chemical effects in the hot zone appears in the work of Aten, who investigated the distribution of oxidation states of formed by the n,p reaction in irradiated inorganic sulfur compounds (S). When he irradiated solid potassium sulfate or sodium sulfate decahydrate, only a few per cent of the recoils were in lower (nonphosphate) oxidation states. With sodium sulfite (hydrated) the percentage rose to about 50%, while for sodium sulfide 65% to 95% were in lower oxidation states. He found similar correlations when the P was produced by the Cl (n,a) process. Here, the irradiation of KCIO3 or KCIO4 produced 99% phosphate, while NaCl gave only 35%. 

In a S-1. round-bottomed flask equipped with a reflux condenser and a mechanical stirrer are placed 236 g. (1.5 moles) of / chloronitrobenzene, 960 g. (4 moles) of sodium sulfide nona-hydrate, and 2.5 1. of water. With rapid agitation, the reaction mixture is slowly heated to the reflux temperature (Note 1). Heating is continued over a period of 20 hours. 

Furnace phosphoric acid is pure enough for most uses as obtained directly from the process. Food-grade applications require removal of traces of arseni-ous oxide (Table 10.6). Arsenic is present to the extent of 50-180 ppm (as AS2O3 equivalent) in the feed phosphorus because of the similarity of its chemical properties to those of phosphorus (same group in the periodic table). This ends up in the product acid on oxidation and hydration [1]. It may be removed by the addition of the requisite amount of sodium sulfide or hydrogen sulfide to the furnace acid, which precipitates it as the arsenic III and V sulfides (e.g., Eq. 10.20). 

Reduction of triarylbismuth dihalides to the parent triarylbismuthines can be performed by using a variety of reducing agents, which include hydrazine hydrate, sodium hydrosulfite, liquid ammonia, LiAlH4, NaBH4, sodium sulfide and sodium dialkyldithiocarbamate. This type of reduction has been used for the purification of tris(3-methylphenyl)bismuthine which is purified with difficulty in the trivalent state [26JA507]. The electrolytic reduction of triphenyl-bismuth dibromide has been found to be a one-step, two-electron process where the bromine atoms are released as bromide ions [66JA467]. 

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