1- Naphthyl phenyl sulfide

A DFT study of the 2 + 2/4 + 2-cycloaddition of benzyne with thiophene to produce 1-naphthyl- and 2-naphthyl phenyl sulfides led to a modification of the originally proposed reaction pathway.1 The reaction of an E-Z mixture of 7-benzylidenecycloocta-1,3,5-triene (1) with TCNE yields a mixture of 2 + 2- [(2) and (3)], 4 + 2- [(4) and (5)], and 8 + 2- (6) cycloadducts. The presence of pentadienyl and homotropylium zwitterions accounts for the products isolated (Scheme l).2... 

A report of 2 + 2- and 4 + 2-cycloadditions of benzyne and thiophene provides several reaction paths to account for the 1-naphthyl and 2-naphthyl phenyl sulfide products. A DFT study of these paths shows that some presumed reaction intermediates are not stable entities. A new reaction path adapting a portion of the literature paths but with a lower activation free energy, is described.2 The 4 + 2 path crosses over from (5) and joins the 2 + 2 path with structure (6). The paths appear to proceed by both 2 + 2 and 2 + 4-additions with equal facility. 

Naphthyl phenyl sulfide is desulfurized to naphthalene on refluxing with lithium aluminum hydride and titanium tetrachloride, and 1-naphthyl ethyl sulfide and 1-naphthyl isopropyl sulfide are converted to naphthalene on treatment with ethanethiol and anhydrous aluminum chloride (equation 83). ... 

Aryl halides containing less reactive halogen can also be converted into sulfides by thiols if heavy-metal (lead, zinc, mercury) thiols are used at 225-230° 1-naphthyl, 2-naphthyl sulfide,301 1- and 2-naphthyl phenyl sulfide,302 and 1-and 2-naphthyl o-, m-, and p-tolyl sulfide303 have been obtained in this way. When the heavy-metal thiolates are too stable and do not react with aryl bromides even at 240°, the aryl sulfides can nevertheless often be prepared by a generally applicable reaction of aryl iodides with sodium thiolates under the influence of copper as catalyst.304... 

Methyl (99%) and ethyl 2-naphthyl sulfide (68%), (2-naphthylthio)acetic acid (87%), and 2-naphthyl phenyl sulfide (43%) have been prepared by the same method. 

Thiophene is generally considered the most aromatic of the five-membered heterocycles, hence its reluctance to function as a diene in cycloadditions. A detailed study of the reaction of thiophene with six common benzyne precursors showed that side reactions with intermediates en route to benzyne often dominate the reaction course. Best results were obtained with diphenyliodonium-2-carboxylate 294, which gave up to 30% yields of naphthalene, presumably mainly through intermediate 295. Other benzyne-derived products [benzo( )thiophene, 0.5% 2-phenylthiophene, trace diphenyl sulfide, trace 1- and 2-naphthyl phenyl sulfides, 9 and 6%, respectively o-(2-thienyl)biphenyl, 4%] bring the... 

The DszC enzyme was able to convert the following compounds other than DBT thioxanthen-9-one, 2,8-dimethyl DBT, 4,6-dimethyl DBT, and 3,4-benzo DBT. Non-organosulfur compounds such as biphenyl, carbazole, and dibenzofuran did not show any activity. This indicates that dszC specifically recognizes sulfur atom [151]. One study specifically examined the DszC enzyme for oxidation of aryl sulfides [179] and reported oxidation of many sulfides including, naphthyl methyl sulfide, phenyl methyl sulfide, and its alkyl derivatives. 

Methyl- or 2-ethyl-benzo[Z> ]thiophenes are conveniently prepared by treatment of 2-benzo[6]thienyllithium with the appropriate alkyl sulfate <70AHC(11)177). Clemmensen or Wolff-Kishner reductions of the 2-acylbenzo[Z>]thiophenes are useful, but since acylation produces a mixture of the 2- and 3-acyl isomers (Section 3.14.2.4), these must be separated. Cyclization of phenyl phenacyl sulfide with hydrofluoric acid leads exclusively to 2-phenyl-benzo[6]thiophene, and 3-phenylbenzo[6]thiophene can be rearranged to the 2-isomer in hydrofluoric acid (Section 3.15.2.3.2). Aromatization of 2-cycIohexenylbenzo[6]thiophene, obtained by condensation of the 2-lithio reagent with cyclohexanone, gives 2-phenyl-benzo[6]thiophene, and the reaction is adaptable to the 2-(l-naphthyl) derivative also. 

A remarkably high diastereoselective excess was obtained in the addition of the anion of (S)-(-)-methyl 1-naphthyl sulfoxide to n-alkyl phenyl ketones. The sulfoxide was prepared in optically pure form by oxidation of the complex of methyl 1-naphthyl sulfide and 13-cyclodextrin with peracetic acid followed by crystallization. Desulfurization of the adducts provided enantiomerically pure tertiary alcohols (393]. 

Attempted preparation of 3-phenylbenzo[6]thiophenes by an extension of the above method invariably proceeds with rearrangement to give the 2-phenyl isomer186,299,303,304,307 308 or a mixture of the 2- and 3-phenyl isomers.186,308 In this case, use of PPA appears to favor formation of the 3-isomer,186,299, 309 whereas use of hydrofluoric acid usually affords the 2-isomer.299 It is interesting to note that 3-phenylbenzo[6]thiophene is converted into its 2-isomer by hydrofluoric acid,290 but is only isomerized to a small extent by hot PPA.186,308 During the cyclization of phenyl phenacyl sulfide to give 2- and/or 3-phenylbenzo[6]thiophene, small amounts of diphenyl disulfide and 5-phenylmercapto-3-phenylbenzo[6]thiophene are also formed.186,209 3,3 -Dibenzo[6]thienyl,305 2,3 -dibenzo[6]thienyl,305 and mixtures of 2- and 3-(2-thienyl)benzo[6]thiophene, 2- and 3-(2-naphthyl)benzo[6]thiophene, and 3-(1-naphthyl)- and 2-(2-naph-thyl)benzo[6]thiophene309 have been prepared by the appropriate modification of the Werner procedure. 

Dimethyl sulfide N,N -Di-P-naphthyl-p-phenylenediamine 2,4-Dinitrophenyl phenyl sulfide Ethyl-N-butylamine 2-Ethylhexanal 2-Ethylhexenal 2-Ethyl-2-hexenal Ethyl vinyl ketone Formamide Glyceryl-a-monochlorohydrin... 

In a number of cases aromatic thioethers can be used for the stabilization of polyolefins however, in most cases their stabilizing effectiveness is low. Of llie best investigated compounds, diphenyl sulfide, phenyl-benzyl sulfide, di-/3-naphthyl sulfide, methyl-/ -naphthyl sulfide [41], sulfides of the thiophene series [28], etc., are known. In most cases amino- or phenol sulfides such as 2,2 -thio-bis-(4-methyl-6-tert-butyl-phenol), thio-bis-/3-naphthol, thio-bis-(N-phenyl-2-naphthylamine) [41], etc., are used. 

Ci,Ru3 o-Tolyl- -naphthyl-8ulfid 8, 622. m-Tolyl-a-naphthyl-suIfid (, 822. p-Tolyl-s-naphthyl-eulfid 8, W2. Benzyl-x-naphthyl.euUid 8, 622. o.Tolyl- -naphthyI.siilfid 8, 658. m-Tolyl./J.naphthyl-suIfid 8, 668, p-Tolyl-d-naphthyl-sulfid 8, 859. 2.BenzyIhy(fiyl.thiophen 17, 82, II82. I nHigSe iMnzyl-z-naphthyl.aelenid 8, 626. C],HnAz Methyl-phenyl-x-naphthyl-arsin 18 II410. 

Since the determination of inhibitors in polymers by Drushel et al. [13] little information has been added to the literature on the quantitative aspects of the direct examination of polymer films by phosphorescence spectroscopy. These authors examined phosphorescence (at liquid-nitrogen temperature) of thin EPR films containing Santonox R (2,2 -di-methyl-5,5 -di-r -butyl-4,4 -dihydroxydiphenyl sulfide) and V-phenyl-2-naphthyl-amine (PBN). The rather intense phosphorescence of PBN may be used to advantage when other additives interfere in the UV absorption method. As to quantitative phosphorescence analysis, several factors, e.g. film thickness, concentration quenching, and background absorption, etc., affect the linearity of the analytical working curves and precision of the measurements [13]. The reliability of a correlation between stabiliser concentration in the film and phosphorescence intensity at 77 K is also influenced by the degree of crystallinity [544]. 

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