Health & Environmental Research Online (HERO)


Print Feedback Export to File
6921967 
Journal Article 
Formation of Diphenyl Sulfoxide and Diphenyl Sulfide via the Aluminum Chloride-Facilitated Electrophilic Aromatic Substitution of Benzene with Thionyl Chloride, and a Novel Reduction of Sulfur (IV) to Sulfur (II) 
Sun, X; Haas, D; Sayre, K; Weller, D; , 
2010 
1 
Phosphorus, Sulfur, and Silicon and the Related Elements
ISSN: 1042-6507
EISSN: 1563-5325 
TAYLOR & FRANCIS LTD 
ABINGDON 
185 
12 
2535-2542 
English 
WOS:000284418300019 
The aluminum chloride (AlCl3)-facilitated electrophilic aromatic substitution (EAS) reaction of benzene (PhH) with thionyl chloride (SOCl2) in the molar ratio of PhH:SOCl2:AlCl3 = 2:1:1 was studied under different conditions. At about 70 degrees C, adding granular AlCl3 (equimolar to SOCl2) piecewise to a 2:1 mixture of PhH and SOCl2 led to formation of a highly pure (99.9%) sole product of diphenyl sulfoxide (Ph2SO) in an isolated yield of 85% after aqueous workup. It represents a simple and very efficient synthesis of Ph2SO, an important fundamental organic reagent. At about 0 degrees C, adding PhH (twice the molar quantity of SOCl2) to a 1:1 mixture of SOCl2 and AlCl3 gave both diphenyl sulfide Ph2S (yield: 37%) and Ph2SO (yield: 27%) after aqueous workup, together with a small amount of S-phenyl benzenesulfonothioate PhSO2SPh (yield: about 5%) and a trace amount of diphenyl sulfone (Ph2SO2). A possible mechanism has been proposed to account for formation of all these products, especially for the formation of Ph2S [S (II)] from SOCl2 [S (IV)], which involves a novel reduction of sulfur in the course of the EAS reaction.