Solvent-Free C-S Bond Formation

Type of reaction C-S bond formation Reaction condition solvent-free 

Keywords sodium dithionite, sodium formaldehyde sulfoxylate, benzyl halide, dibenzyl sulfone 

Benzyl bromide (17.1 g, 0.1 mol) was added to a mixture of solid sodium dithionite (10.44 g, 0.06 mol) and Aliquat 336 (1.2 g, 0.03 mol). The mixture was vigorously shaken for 5 min and then heated in an oil bath for 20 h at 120 °C. Dibenzyl sulfone was removed by filtration through Florisil with 50 mL of methylene chloride. The solvent was evaporated and the crude solid crystallized from a 1 1 mixture of ethanol and toluene to give the pure sulfone as a white solid (7.54 g, 61%), mp 148-149 °C. 

An analogous procedure was carried out with benzyl bromide (17.1 g, 0.1 mol), sodium formaldehyde sulfoxylate dihydrate (10.35 g, 0.06 mol) and sodium carbonate (10.35 g, 0.075 mol) to obtain the pure dibenzyl sulfone (9.35 g, 76% after recrystallization). 

References A. Loupy, J. Sansoulet, A.R. Harris, Synth. Commun., 19, 2939 (1989). 

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Solvent-Free C-S Bond Formation under Microwave Irradiation 335... 

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