Reductions with sodium sulfide

Diaminoamhraquinone is prepared from 1.5-dmitroanlhraquinone by ammonnlysis, by catalytic hydrogenation, or by reduction with sodium sulfide. It is also prepared From anthraquinone-],5-disulfonic acid by ammonolysis. 1.5-Diaminoanlhraquinone is an important intermediate lor manufacturing vat dyes. 

The only known substituted tellurantrene is perfluorotellurantrene 101. Its adduct with two molecules of bromine, 5,5,10,10-tetrabromoperfluoro-tellurantrene, was isolated in 29% yield when o-diiodotetrafluorobenzene was allowed to react with elemental tellurium and then bromine was added to the reaction mixture (80JFC245). A subsequent reduction with sodium sulfide affords 101 in rather low 20% yield, unusual for the typically smooth reduction of cr-telluranes. 

Sulfur Dyes (C.I. Sulphur). Two types of sulfur dyes exist amorphous powders, which are insoluble or partially soluble in water. They must be brought into solution by reduction with sodium sulfide, according to Equation (5). 

The reductions with sodium sulfide proceed when the reactants are heated to 100° without solvents. Sensitive organo tellurium trihalides might be decomposed by some of these reducing agents. /J-Chloroalkyl tellurium trichlorides are converted to olefins upon treatment with sodium sulfide, whereas y-chloroalkyl tellurium trichlorides are reduced to ditellurium products1. 2-Alkoxyalkyl tellurium trichlorides are reduced without difficulty by sodium disulfite to bis[2-alkoxyalkyl] ditellurium compounds2. 

The preparative reduction, polarography, and cyclic voltammetry of 5-methyl-l,2-dithiole-3-thione have been studied.171 The results obtained are in agreement with a one-electron reduction of the thiocarbonyl group to a radical-anion, which could not be detected by ESR spectroscopy as it dimerizes too fast. The dimer is further reduced by a one-electron reduction to an anion in which the ring has been opened. (Scheme 12). The dianion could be isolated after methylation and was found to be identical with the compounds isolated by Maignan and Vialle by reduction with sodium sulfide.124 The dianion corresponds to the thioketonate dianion obtained by electrochemical reduction of 1,2-dithiolylium salts.172... 

Phenothiatellurins are synthesized by heating 2-trichlorotellurophenyl phenyl sulfides thus, phenothiatellurin is obtained when 2-trichlorotellurophenyl phenyl thioether (103) is heated at 240-250 °C and the intermediate (104) is dechlorinated by reduction with sodium sulfide (Scheme 27) <60T15>. 

The compound can be prepared from 2,4,6-trinitrophenol (picric acid [88-89-1]) by reduction with sodium hydrosulfide (163), with ammonia —hydrogen sulfide followed by acetic acid neutralization of the ammonium salt (164), with ethanolic hydrazine and copper (165), or electrolyticaHy with vanadium sulfate in alcoholic sulfuric acid (159). Heating 4,6-dinitro-2-benzamidophenol in concentrated HQ. at 140°C also yields picramic acid (166). 

This compound can be converted to l,5-diamino-4,8-dihydroxyanthraquiaone by reduction of nitro groups with sodium sulfide. 

Compounds 15 can be prepared either by acylation of bis(o-aminophenyl) ditelluride (88KGS276 89KGS120) or by reduction of A -acyl-2-trichlorotelluro-benzenes with sodium sulfide (88MI1). 

Dibenzo[d,g][l,5]telluroazocines 65 are the only representatives of Te, N-containing eight-membered heterocycles known thus far. Treatment of bis(2-bromomethylphenyl)tellurium dibromide 66 with methylamine followed by reduction of the reaction mixture with sodium sulfide gives, instead of the expected... 

The last reaction perhaps involves an intermediate such as 33a which expells a proton and dimethyl sulfide. Formation of the Schiff s base with t-butylamine, reduction with sodium borohydride and hydrogenolysis of the benzyl ether produces sulfonterol (28). Despite the fact that the methylene hydrogen of sulfonterol must be much less acidic than of the corresponding urea proton on carbuterol or the sulfonamide proton on soterenol, good bioactivity is retained. 

Tertiary nitro compounds are converted into the corresponding thiols by the reaction with sodium sulfide and sulfur (S8) in DMSO followed by the reduction with Al-Hg. (Eq. 7.12). Secondary and primary nitro compounds do not give thiols in these reactions instead, a complex set of product is formed.13... 

Andreae [324,325] has described a gas chromatographic method for the determination of nanogram quantities of dimethyl sulfoxide in natural waters, seawater, and phytoplankton culture waters. The method uses chemical reduction with sodium borohydride to dimethyl sulfide, which is then determined gas-chromatographically using a flame photometric detector. 

Yu and Bailey (1992) studied the reaction of nitrobenzene with four sulfide minerals under anaerobic conditions. Observed half-lives of nitrobenzene were 7.5, 40, 105, and 360 h for the reaction with sodium sulfide, alabandite (manganese sulfide), sphalerite (zinc sulfide), and molybdenite (molybdenum sulfide), respectively. Aniline and elemental sulfur were found as reduction products of nitrobenzene-manganese sulfide reaction. Aniline was also a reduction product in the nitrobenzene-molybdenum sulfide and nitrobenzene-sodium sulfide reactions. Several unidentified products formed in the reaction of nitrobenzene and sphalerite (Yu and Bailey, 1992). 

More reliable reagents for the preparation of sulfinic acids are zinc [694, 695], sodium sulfide [249] and sodium sulfite [2S2. These reagents not only stop the reduction at the stage of the sulfinic acids (in the form of their salts) but do not reduce other functions present in the molecules. In the reduction of anthraquinone-l,5-disulfonyl chloride with sodium sulfide below 40° anthraquinone-l,5-disulfinic acid was obtained in 83.5% yield [249], and p-cyanobenzenesulfonyl chloride was reduced to p-cyanobenzenesulfinic acid in 87.4% yield [252]. 

Zwanenburg and Wynberg also proposed another route to the thienothiophene (112). 2,5-Dibromo-3,4-bisbromomethylthiophene (116) was cyclized with sodium sulfide to give 4,6-dibromo-l f,3/f-thieno[3,4-c]thiophene (117) in 60% yield 117 was then reduced to thienothiophene (112). l,3,7,9-Tetrabromo-4i/,67f,10.H, 12ff-dithieno-[3,4 C 3, 4 -/i][l,6]dithiecin (118) (18%) was also formed during the ring closure. Oxidation of thienothiophene (117) followed by reduction by zinc in acetic acid gave l/f,3H-thieno[3,4-c]thiophene 2,2-dioxide (119). ... 

Phthalimide protection is stable towards acids and bases, but can be cleaved with strong nucleophiles, such as hydrazines or sulfides, or by reduction with sodium boro-hydride [230]. More sensitive towards nucleophilic attack than unsubstituted phthalimide is tetrachlorophthalimide [33]. This group has been successfully used as N(a) protection of amino acids in the solid-phase synthesis of peptides (deprotection N2H4/DMF (15 85), 40 °C, 1 h coupling DIC/HOAt/amino acid (1 1 1), 3 equiv. of each, DMF, 25 °C, 4 h [294]). Typical conditions for the removal of phthaloyl protection on cross-linked polystyrene include treatment of the resin with hydrazine hydrate [295,296], with methyl hydrazine [297], or with primary aliphatic amines [298] in DMF, EtOH, or solvent mixtures for several hours at room temperature or above [296,299,300]. Illustrative examples are sketched in Figure 10.15. It has been claimed that the hydrazinolysis of polystyrene-bound phthalimides proceeds more readily in DCM or DCE than in DMF [301]. 

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