Thianthrene intermediate

A different approach leading to thianthrene derivatives starts from 0-ethyl or 0-isopropyl dithiocarbonate 394, when heated with chlorodinitrobenzene derivative 59 provided intermediate 395, the compound having all features necessary for denitrocyclization reaction to the final product 396, which was the only isolated compound (Scheme 61). Its structure was assigned by X-ray crystallography (77JOC2896). 

Oxidation of T to generate thianthrene 5-oxide occurs cleanly with nitrite and nitrate (72JOC2691). Incorporation of 0 from labeled nitrite was considered consistent with a process (arrows on 31) involving 31 as an intermediate and producing NO as byproduct. 

The substitution of thianthrene with radicals does not appear to have been examined. Reaction with at 320°C produced thianthrene in which 83% of the sulfur had been exchanged an intermediate of the form 51 was suggested (73BCJ650). 

A completely different reaction to give 1,2-dilithio synthons was performed by double lithiation of thianthrene 426 (Y = S) under catalytic conditions. Thus, after the first lithiation with lithium and DTBB (4%) in THF at —90 °C, the corresponding intermediate (of... 

Dibenzo[6,e][l,4]dioxin, phenoxathiin and thianthrene all react with butyllithium with proton abstraction from a benzene ring. Dibenzo[f ,e][l,4]dioxin and thianthrene are metallated at the 1-position (128), while lithiation of phenoxathiin occurs ortho to the C—O bond rather than the C—S bond, i.e. at C-4, (129). The lithiated products provide excellent intermediates for functionalizing the rings at these positions, usefully complementing the product distribution pattern in electrophilic substitution reactions. 

Other Organosulfur Compounds. There have been reports of the microbial metabolism of other OSC. However, few of these studies have given the identities of intermediates or organic endproducts of the OSC. For example, aerobic cultures have been reported to remove sulfur from phenyl sulfide (62). Thioxanthene and thianthrene were transformed to water-soluble products by a dibenzothiophene-oxidizing bacterium (48). In addition, thianthrene and thioxanthene served as sole carbon sources for the aerobic thermophile S. acidocaldarius (69) which released sulfate from these compounds. 

The initial formation of the benzodithiete 19e, as an intermediate in the reaction of benzyne with elemental sulfur, was suggested on the basis of its secondary reaction that traps another benzyne molecule to give thianthrene 139, or o-C6U4S2 19e to give tetrathiocin 140 (Scheme 17) <2004JOC5483>. 

The central ring of both dibenzo[l,4]- dithiins and -oxathiins is cleaved on treatment with Li and a catalytic amount of 4,4"-di-rert-butylbiphenyl (DTBB) to afford thiols after reaction of the dilithio intermediate with electrophiles. In certain instances, the initial product can be cyclised to the dibenzo- dithiepine and -oxathiepine <02CL726>. The dilithio salt from thianthrene reacts sequentially with two different carbonyl compounds to give a l,2-di(hydroxyalkyl)benzene. When C02 is used as the second electrophile, a phthalan results <02TL7205>. 

Peroxide complexes of molybdenum(VI) are intermediates in industrially important epoxidation reactions. The so-called Mimoun-type complexes [Mo 0(02)2LaxLeq]° " (12) generally exhibit pentagonal-bipyramidal structures, with an axial 0x0 group trans to Lax and Leq, and two peroxo groups in the equatorial plane. These complexes are effective reagents for the selective oxidation of alcohols to aldehydes, amines to nitroso compounds, sulfldes to sulfoxides and then to sulfones, phenols to o-quinones, and in the sulfoxidation of thianthrene-5-oxide. 

The DTBB-catalyzed lithiation of 4-hetero-substituted dibenzothiins (68), such as phenoxathiin (68a), phenothiazine (68b) and thianthrene (68c), at low temperature gives the corresponding functionalized organolithium intermediates (69), which by reaction with different electrophiles afford, after hydrolysis, the expected functionalized... 

The major intermediate compound in the polymerization of benzene and sulfur is thianthrene and the same polymer can be made with thianthrene as the starting material. Therefore, the conclusion can only be that the polymer consists of thianthrene units connected by sulfide linkages with an... 

Intermediates in the thermal oxidations of thioethers with NO are generally difficult to detect owing to the limiting reaction rates. The exceptions are oxidations of strong sulphur-containing donors derived from thianthrene. The stoichiometric oxidation of thianthrene in dichloromethane at -78 °C produces a pink-coloured solution ( max =-544 nm) that finally leads to a pale-yellow solution from which thianthrene 5-oxide was isolated in 94% yield. This process involves the intermediate stage of the thianthrene radical cation formation [23] ... 

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