Preparation, structure, and some properties of the sulfoxide of thiaxanthone

Castrillon, Jose; Szmant, H. Harry

doi:10.1021/jo01279a028

Cited by 49 publications

(7 citation statements)

References 2 publications

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“…The formation of compounds 13b and 13c may be explained by taking into account the possible conformational isomerism of the isopropyl-thioxanthenone scaffold. In the past, Castrillón and Szmant (1966) failed in their attempt to separate 9H-thioxanthen-9-one sulfoxide isomers by TLC, it being impossible to distinguish between the structures with the axial or equatorial sulfur-oxygen bond, probably due to the too low energy barrier of "flapping". We speculated that the presence of isopropyl substituent, in addition to the sulfinyl functional group, caused four stereisomers to be formed ( Figure 8), which can be separated by chiral liquid chromatography S5 (supporting information).…”

Section: Discussionmentioning

confidence: 99%

“…The oxidation of 2-ITX resulting in the formation of the same products was also obtained using the biomimetic oxidants 5,10,15,20-tetraphenyl-21H,23H-porphine manganese(III) chloride or 5,10,15,20-tetraphenyl-21H,23H-porphine iron(III) chloride in the presence of hydrogen peroxide. On the contrary, 9H-thioxanthen-9-one scaffold was more selectively converted to sulfoxide derivative using (diacetoxyiodo)benzene reagent (see synthesis of compound 11) as previously reported (Castrillón and Szmant, 1966). Compounds 13b and 13c were characterized by a very similar UV spectra whereas MS 2 data showed the protonated molecule [M+H] + at m/z 271 and the fragment ions at m/z 254 and 229, suggesting the presence both of a sulfoxide function and of an unmodified isopropyl group, respectively (Table 1).…”

Section: Synthesis Of Putative Metabolitesmentioning

confidence: 97%

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In vitrometabolism study of 2-isopropyl-9H-thioxanthen-9-one (2-ITX) in rat and human: evidence for the formation of an epoxide metabolite

2010

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1. 2-Isopropyl-9H-thioxanthen-9-one (2-ITX) is one of the most extensively used photoinitiators in inks found in paper and/or packaging materials for foodstuffs. Recently, traces of 2-ITX as a contaminant were discovered in baby milk and other foodstuffs at a level sufficient to pose a risk to human health. However, little is known about the toxicological profile of 2-ITX. 2. The high lipophilicity of this substance would suggest that it could be a good substrate for hepatic metabolizing enzymes and that these metabolites could have a role in the toxicological properties of 2-ITX. 3. The metabolism of 2-ITX, using both rat and human subcellular preparations, was studied and has resulted in the formation of eight polar metabolites (M1-M8) as revealed in the liquid chromatograpy/ultraviolet (LC/UV) and liquid chromatograpy/mass spectrometry (LC/MS) analyses. Their structures highlight a marked regioselectivity in the metabolism of 2-ITX; it is directed mainly toward the isopropyl moiety and the sulfur atom. 4. The unsaturated metabolite 6 causes the formation of a reactive epoxide metabolite 7. This finding was supported by identification in microsomal incubations of 1,2-diol metabolite 8 arising from the epoxide by hydrolysis and it was validated by incubating in the same conditions the synthetic epoxide 7: the formation of metabolite 8 was again observed. 5. On the basis of these data, we propose that the metabolite 6 could be included in toxicological studies of 2-ITX.

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Section: Discussionmentioning

confidence: 99%

Section: Synthesis Of Putative Metabolitesmentioning

confidence: 97%

In vitrometabolism study of 2-isopropyl-9H-thioxanthen-9-one (2-ITX) in rat and human: evidence for the formation of an epoxide metabolite

2010

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“…Initial research suggested thianthrene was folded about the S-S axis, in line with a dipole moment of 1.5 D, although flexibility of the molecule permits the folding to be undergo facile inversion, 1,2 with an energy barrier estimated to be 6-7 kcal/mole. 3,4 X-Ray measurements on crystalline thianthrene indicated the solid state structure consists of puckered and interleaved layers of molecules ( Figure 2); 2,5 the atoms of each molecule lie in two planes which intersect at the S-S axis to form a dihedral angle of 128° (Figure l). 6,7,8 This conformation enables the sulfur atoms to retain their "natural" valency angle of ca 100°, similar to that found in 1,4-dithiadiene.…”

Section: Properties Of Thianthrenementioning

confidence: 99%

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confidence: 99%

Thianthrene-Containing Polymers: Polyimides, Aramids, and Polybenzoxazoles

Johnson

Mathias

1996

Step-Growth Polymers for High-Performance Materials

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Thianthrene and thioether-containing aromatic dicarboxylic acids were readily synthesized by nucleophilic aromatic substitution. Polyamides obtained from the diacids displayed good thermal stabilities and solubilities enhanced over typical aramids. Films displayed good toughness and flexibility, consistent with high molecular weight and low crystallinity.Thianthrene-2,3,7,8-tetracarboxylic dianhydride was prepared starting from dichlorophthalic acid, making the N-phenylimide and forming the thianthrene ring with either thioamides or sodium sulfide. Polyimides were synthesized by the low temperature formation of poly(amic acid) solutions which were cast into films and then thermally cyclized. Flexible diamines gave creasible films while rigid diamines gave brittle films, with excellent thermal stability. Polymer solubility was not enhanced by incorporating the bent thianthrene structure.New thianthrene-containing PBOs were synthesized by the polycondensation reaction of thianthrene dicarbonyl chlorides with bis -o-aminophenols in PPA. The PBOs exhibit high glass transition temperatures and good thermal stabilities. No solubility improvements were observed but films were transparent and tough. Properties of ThianthreneThianthrene is a semi-flexible ring system comprised of two benzene rings bonded through vicinal sulfides (structure and numbering system shown in Figure 1). Initial research suggested thianthrene was folded about the S-S axis, in line with a dipole moment of 1.5 D, although flexibility of the molecule permits the folding to be undergo facile inversion, 1,2 with an energy barrier estimated to be 6-7 kcal/mole. 3,4 X-Ray measurements on crystalline thianthrene indicated the solid state structure consists of puckered and interleaved layers of molecules ( Figure 2); 2,5 the

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“…9 Unfortunately, most of the methods used have certain limitations such as hazardous, toxic reagents and metal toxicity accompanied by over oxidation to the sulfone and high price of catalysts. [10][11][12][13][14] Moreover, a challenge in this reaction could be the complete selectivity for sulfoxide products. Although some homogeneous tribromide has been found to be effective for oxidation of suldes, still they have certain limitations.…”

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confidence: 99%