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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: sayantan dutta on August 28, 2020, 03:16:33 AM

Title: chlorination with SO2cl2
Post by: sayantan dutta on August 28, 2020, 03:16:33 AM

for allylic chlorination .SO2Cl2 is used but not N chloro succinide(NCS)
but for allylic bromination NBS is the best choice to use
why NCS not used ?

Title: Re: chlorination with SO2cl2
Post by: chenbeier on August 28, 2020, 04:19:59 AM

I think it is vise versa. SO₂Br₂ is not existing, so NBS can only be used. For chlorination SO₂Cl₂  is existing and can be used. NCS is also possible.

Title: Re: chlorination with SO2cl2
Post by: sayantan dutta on August 28, 2020, 04:28:56 AM

yes ncs can also be used but not a best choice ....my question is why it's not a best choice .

Title: Re: chlorination with SO2cl2
Post by: Babcock_Hall on August 28, 2020, 10:17:23 AM

If you are planning to use SO₂Cl₂, my suggestion is to distill it shortly before use.  There was a low boiling impurity, at least the material that I had.  If this is purely a hypothetical exercise, then please excuse the intrusion.