Comparisons of reactivities in photolysis and thermolysis reactions of 1,9-bis(alkylthio)dibenzothiophenes with stabilities of their dithia dications in concentrated sulfuric acid

✍ Scribed by Takeshi Kimura; Yukiko Izumi; Ernst Horn; Naomichi Furukawa

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 909 KB
• Volume: 7
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/(sici)1098-1071(199610)7:5<313::aid-hc6>3.0.co;2-c

✦ Synopsis

I , 9-Dithia substituents in dibenzothiophenes are in close proximity, being within the van der Waals S-S contact distance (3.70 A) [I], and hence, these two sulfur atoms affect each other by strong through-space interaction. Cyclic and acyclic dibenzothiophene derivatives bearing two sulfur atoms at the 1,9-positions, such as dibenzothiophene[l,9-fgh][l,5]dithionin ( 5 ) and I , 9-bis(methylthio)dibenzothiophene (1 a) and their monosulfoxides 2a and 6 were treated with concd sulfuric acid as an oxidizing or deoxygenating reagent to produce the corresponding dithia dications 7 and 3a. The dithia dications 3a and 7 in concd sulfuric acid gave the monosulfoxides upon treatment with water. On the other hand, a rapid monodealkylation reaction proceeded in the case of 1,9-bis(ethyb thi0)dibenzothiophene (1 b) and I , 9-bis(isopro-py1thio)dibenzothiophene (lc) and their monosulfoxides, on dissolution in concd sulfuric acid, afforded Dedicated t o Professor Louis D. Quin on the occasion of his