Sulfides benzyl

A solution of 116 g. (0.92 mole) of benzyl chloride in 300 ml. of 95% ethanol is heated on a steam bath and stirred while a solution of 35 g. (0.45 mole) of sodium sulfide in 100-125 ml. of water is added. Stirring and heating are continued for 3 days, after which the ethanol is distilled off and the residue is poured on 700 g. of crushed ice. The precipitated oil is separated and heated under vacuum to remove water and benzyl chloride. The residue is recrystallized from 70% ethanol to give 48 g. (83%) of benzyl sulfide, m.p. 49°. 

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Two efficient syntheses of strained cyclophanes indicate the synthetic potential of allyl or benzyl sulfide intermediates, in which the combined nucleophilicity and redox activity of the sulfur atom can be used. The dibenzylic sulfides from xylylene dihalides and -dithiols can be methylated with dimethoxycarbenium tetrafiuoroborate (H. Meerwein, 1960 R.F. Borch, 1968, 1969 from trimethyl orthoformate and BFj, 3 4). The sulfonium salts are deprotonated and rearrange to methyl sulfides (Stevens rearrangement). Repeated methylation and Hofmann elimination yields double bonds (R.H. Mitchell, 1974). 

Chromium atoms were cocondensed with benzyl sulfide at 77 K (35), the primary result being desulfurization to form bibenzyl and trans-stilbene. Coordination compounds were not characterized in this system. 

Conversion of sulfones such as 1955 into their a-sulfonyl anions by treatment with n-BuIi at -78°C in THF then addition of bis(trimethylsilyl)peroxide (BTSP) 1949 afford, via intermediates such as 1956, aldehydes or ketones such as cyclohexanone and HMDSO 7 [146]. This reaction has subsequently been applied to the synthesis of aldehydes [147]. After hthiation with -BuLi thioethers such as phenyl benzyl sulfide 1957 react with BTSP 1949 to give mixtures of the O-silyl 1958 and C-silyl 1959 products [148]. On treatment with -BuLi at -30°C the a,a-bis-(trimethylsilyl)dimethylsulfide 1960 is, hkewise, converted into its anion, which reacts with 1949 to give the a-trimethylsilyloxy sulfide 1961 and MesSiOLi 98 [149] (Scheme 12.41). 

Methyl sulfide, benzyl sulfide, phenyl sulfide... 

The procedure described is essentially that of Ballard and Dehn.1 Stilbene has also been prepared by reduction of desoxy-benzoin,20 benzaldehyde,23 and benzil 2o-2c by dehydrogenation of ethyl benzene,30 toluene,30- 33- 3, and bibenzyl 33-3alkaline reduction of phenylnitromethane,40 phenylnitroacetonitrile,40 and desoxybenzoin 43 by distillation of benzyl sulfone,50 benzyl sulfide,60-63 calcium cinnamate,5 cinnamic acid,5d phenyl cinna-mate,6e-6/ and diphenyl fumarate ie by dehydrohalogenation of a,a -dichlorobibenzyl60 and benzyl chloride 63 by dehalogenation of a,a,c/,a -tetrachlorobibenzyl70 and benzal chloride 73 by the coupling of cinnamic acid and phenyldiazonium chloride 8 by de-... 

The reaction described is of considerable general utility for the preparation of benzoyloxy derivatives of unsaturated hydrocarbons.2"8 Reactions of 2-butyl perbenzoate with various other classes of compounds in the presence of catalytic amounts of copper ions produce benzoyloxy derivatives. Thus this reaction can also be used to effect one-step oxidation of saturated hydrocarbons,9, 10 esters,6,11 dialkyl and aryl alkyl ethers,12 14 benzylic ethers,11,15 cyclic ethers,13,16 straight-chain and benzylic sulfides,12, 17-19 cyclic sulfides,11,19 amides,11 and certain organo-silicon compounds.20... 

B. 2,4-Dinitrobenzenesulfenyl chloride. Dry 2,4-dinitrophenyl benzyl sulfide (232 g., 0.80 mole) and 400 ml. of dry ethylene chloride are placed in a 2-1., one-necked, round-bottomed flask equipped with a stirrer (Note 3). Sulfuryl chloride (119 g., 0.88 mole) (Note 4) is added to the resulting suspension at room temperature. A mildly exothermic reaction causes the solid to dissolve quickly, usually within 1 to 2 minutes, with a temperature rise of 10-15° (Note 5). The resulting clear yellow solution is concentrated to an oil by heating under aspirator vacuum on a steam bath (Note 6). Caution Do not heat with gas or electricity because the product, like many nitro compounds, can explode if overheated.) The residual oil is cooled to 50-60°, and 3-4 volumes of dry petroleum ether (b.p. 30-60°) are added with vigorous handswirling. The oil quickly crystallizes. The mixture is cooled to room temperature and filtered to separate 2,4-dinitrobenzene-sulfenyl chloride as a yellow crystalline solid. The sulfenyl chloride is washed well with dry petroleum ether and dried at 60-80° (Note 7) weight 150-170 g. (80-90%) m.p. 95-96° (Notes 8, 9). 

Dinitrophenyl benzyl sulfide has been prepared by the reaction of benzyl chloride with 2,4-dinitrothiophenol2 or bis-(2,4-dinitrophenyl) disulfide2 and by the condensation of 2,4-dinitrochlorobenzene with benzyl mercaptan.4... 

The chlorinolysis of 2,4-dinitrophenyl benzyl sulfide gives a good yield of product which is satisfactory for most purposes without recrystallization. Only simple equipment and inexpensive materials are needed, only 2 or 3 hours of the operator s time are required, and the entire procedure can be completed within 24 homs. 

Benzyl isocyanide, 41, 14 Benzyl mercaptan for synthesis of 2,4-dinitrophenyl benzyl sulfide, 44, 48... 

A. 2,4-Dinitrophenyl benzyl sulfide. The apparatus consists of a 1-1., three-necked, round-bottomed flask equipped with a sealed... 

The 2,4-dinitrophenyl benzyl sulfide normally undergoes cleavage at room temperature without the addition of a catalyst. If the reaction does not occur spontaneously, the mixture may be warmed gently and/or one drop of dry pyridine may be added to initiate the reaction. 

Dinitrobenzenesulfenyl bromide may be similarly prepared by refluxing 2,4-dinitrophenyl benzyl sulfide with the equivalent amount of bromine in 5 parts of dry carbon tetrachloride. As it is less stable than the chloride, losing bromine if overheated, it should be concentrated on a 40° water bath under vacuum. When worked up in the same manner as the chloride, the product usually contains some is-(2,4r-dinitrophenyl) disulfide. Because the disulfide is insoluble in carbon tetrachloride, the sulfenyl bromide may be readily purified by recrystallization yield 75-80%, m.p. 102-104°. 

The relative ease with which aryl benzyl sulfoxides undergo homolytic dissociation (Rayner et al., 1966) as compared to aryl benzyl sulfides or sulfones is supportive of this idea that ArSO radicals are easier to form than ArS or ArS02 radicals. Another interesting set of observations is the following. Booms and Cram (1972) found that optically active arene-sulfinamides ArS(0)NRPh (R = H or CH3) racemize thermally very readily at room temperature and that this racemization is the result of a free radical chain reaction (160) that is initiated by the dissociation of some of the sulfinamide into an ArSO and a PhNR radical (159). While the length of the inhibition... 

Benzyl sulfides are not desulfurized but reduced to mercaptans. From alkali salts. 

SULFIDE SYNTHESIS BENZYL SULFIDE (Benzene, l,l-[thiobis(tnethylene)]bis-)... 

After 1 hour, the reaction is complete as monitored by gas chromatographic analysis on an Hewlett-Packard F M 5751 research chromatograph (1.85 m. x 0.313 cm. stainless-steel column of 10% Apiezon L on Chromosorb W AW/DMCS column temperature 250°). Thin-layer chromatography was found to be of little use in monitoring the reaction, as the Rf values for benzyl disulfide and benzyl sulfide are virtually identical for a variety of solvent systems tried. Proton magnetic resonance (benzene) shows that these two compounds have coincidental chemical shifts for the benzylic protons 8 3.4 (singlet). 

The volume of column packing used represents a length-width ratio of ca. 10 1. Since column efficiency improves as the length-width ratio is increased (for a given volume of packing), these approximate dimensions should be maintained. For example, when a length-width ratio of ca. 9 1 was applied (with the same amount of silica gel), there was not complete separation, and the yield of pure benzyl sulfide was less than optimum (93%). 

The solidified residue is homogeneous by gas chromatography, and its infrared and nuclear magnetic resonance spectra and gas chromatogram are identical to those of recrystallized authentic benzyl sulfide. The product may be recrystallized in ca. 25 ml. of absolute ethanol to yield colorless plates, m.p. 47-48° (literature3 m p 50°), which give a satisfactory combustion analysis... 

HEXAHYDRO - 4a,5 - DIMETHYL - 2(3H) - NAPHTHALE-NONE and 2-TRIMETHYLSILYLOXY-1,3-BUTADIENE AS A REACTIVE DIENE DIETHYL trans -4-TRIMETHYL-SILYLOXY-4-CYCLOHEXENE-1,2-DICARBOXYLATE. Sulfur substitution also continues to be of high interest, and three preparations on sulfide synthesis are included BENZYL SULFIDE DIALKYL AND ALKYL ARYL SULFIDES NEOPENTYL PHENYL SULFIDE and UNSYMMETRICAL DIALKYL DISULFIDES sec-BUTYL ISOPROPYL DISULFIDE. 

Historically, this represents the first thiophene synthesis, when Laurent obtained tetraphenylthiophene by heating polymeric thiobenzaldehyde in 1844. Almost any aromatic methyl derivative can be converted to tetraphenylthiophene, which is thermodynamically the most stable thiophene, by heating with sulfur. Toluene, phenylacetic acid, benzyl alcohol, benzyl sulfide or disulfide, benzyl sulfonate or even sodium thiobenzoate have been converted to tetraphenylthiophene under these conditions (52HC(3)l). 

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