[rmenghani4]

Does anyone happen to know if DMSO and SoCl2 can react in a similar manner?  I know that if a pair of electrons attacks the S in Socl2, then one Cl will be kicked off, but does the same thing happen with DMSO?  If a pair of electrons attacks the S, does a methyl leave?

[mir]

Its all a question about leaving groups and electronegativities.
Is chloride a better leaving or less better leaving group than methyl?
Which substituent is more electronegative?
How does the electronegativities affect the sulphur atom?

[rmenghani4]

Chlorine is a much better leaving group than methyl.  I think that chlorine is much more electronegative than carbon.  I don't really know how the electronegativities affect sulfur.  I was hoping if anyone knew a link to a page on a website that said that DMSO and SoCl2 reacted similarly.

[mir]

By your conclusions, DMSO dont react similarly with SOCl2. And why? Because SOCl2 have a better leaving group, and the bond between sulphur and chlorine is weak because of the electronegativity differences. And besides that, the sulphuratom is very electronpoor because of the electronwithdrawing groups attached to it (Oxygen and chlorine is EWG's).

[mkaplan4]

DMSO is a very stable solvent, with a high boiling point that has a wide versatility. Acids can be dissolved in DMSO without acyl chloride formation. Thionyl Chloride on the other hand is a nasty, volatile reagent. Like the others said, methyl is not a good leaving group. To kick the CH3- group out would produce an extremely strong base/nucleophile, and wouldn't happen. 

[AWK]

DMSO reacts with SOCL2. This mixture is used (as far as I remember) for converting sulfonic acids to their acid chlorides