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- Jun 30, 2005
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I learned from my OCHEM class and Destroyer that
R-OH + SOCl2 ==> R-Cl
but according to the picture from Kaplan,
R-OH + SOCl2 ==> R-OSOCl
why does this happen? is there an exception to this rule?
a common method of converting OH to alkyl halides involves the formation of inorganic esters, which readily undergo SN2 rxns. alcohols react with thionyl chloride to produce an intermediate inorganic ester (a chlorosulfite) and HCl. the chloride ion of HCl displaces SO2 and regenerates Cl-, forming the desired alkyl chloride.
the strucutre u have is correct except its NOT finished!!! another mole of Cl- will attack the methyl group in ur structure. thus the end products of ur reaction will be: ClCH3 + SO2 + Cl-
I am not sure if I fully understood what you guys said.
The way I understand now is
R-OH + SOCl2 ==> R-O-SOCl + HCl (This is the picture I posted)
and then it's not done yet and we add SOCl2 again,
R-O-SOCl + SOCl2 ==> R-Cl (This is the final product that DAT destroyer shows?)
am I right? and if so, how do I know if I should stop the reaction before the 2nd SOCl2 comes or not?
THIS HAPPENS:
R-OH + SOCl2 ==> R-O-SOCl + HCl
THEN: Cl- attacks the R group. At the same time, Cl leaves the S and the sulfur is oxidized to SO2.
I think I understand the whole mechanism now Thanks.
Another question I have is, how do I know if it will stop at
R-O-SOCl and proceed to the next reaction
or if it will go all the way to R-Cl and then proceed to the next reaction?
In other word, what if the question asks for the product and the answer choices are
1) R-OSOCl
2) R-Cl
which one should I pick?
Thank you all. U guys are genius.