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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Limon on January 05, 2022, 07:43:59 AM

Title: NBS addition to double bond in polar solvent
Post by: Limon on January 05, 2022, 07:43:59 AM
NBS always have some trace amount of HBr present it. During the reaction Alkene+ NBS+H2O... BrOH form which reacted with double bond to give bromohydrin and succinimide as the product.....my question is the trace amount of HBr present in NBS what role does it have in this reaction ?? will it stay unreactive in polar solvent or not? if not what will it do and it's outcome?

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Title: Re: NBS addition to double bond in polar solvent
Post by: phth on January 05, 2022, 11:52:51 PM
It is a pretty low quantity that is generated catalytically in a reaction. HBr catalyzes the decomposition of NBS to elemental bromine. Seems if you are going to have a problem with HBr in cat. quantities, then you will have a problem with Br2 itself. NBS is just a version of elemental bromine that can easily be weighed out. I used to just distill bromine and dole out small volumes like 1.5 uL in some carrier solvent. Why can't an exogenous base be used?