Free Radical Chlorination of Alkanes

by James

Description: Alkanes treated with chlorine gas (Cl2) and light (hv) or heat will be converted into alkyl chlorides.
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{ 13 comments… read them below or add one }

chris raabe February 20, 2012 at 7:21 am


I enjoyed the preacher voice and thought it was hilarious. An entire video in this voice would be funny, if you can sustain it. The real, absolute treasure of this and all of your videos, is the iron-clad stamina you grind out in carefully explaining each step for us. This commitment to clarity and simplicity is a driving sense of beauty so many of us appreciate but are just too busy to stop and thank you.


james February 20, 2012 at 3:01 pm

Thank you very much.


Marina April 20, 2012 at 7:15 pm

Chris is right. Thank you for the passion in your teaching! It rubs off onto the students . . .


Nick October 17, 2012 at 10:21 pm

Thanks for the videos. Very helpful.

In the second example you start with propane. The description of the mix of products that results refers to butane. Not a big deal though.


james October 18, 2012 at 5:31 pm

Oh snap. Thank you.


Kris February 6, 2013 at 9:14 am

The image in the first example is unrelated to this reaction.


james February 6, 2013 at 12:01 pm

Fixed. thank you!


studier May 15, 2013 at 10:55 am

The relative rate of chlorination products is not only related to the number of primary, secondary, and tertiary hydrogens on each carbon, but also the tendency of radical formation at primary, secondary, and tertiary carbons. Relative rates of chlorination -> 5 at tertiary, 3.8 at secondary, 1 at primary. I just pulled those from memory, someone double check. Bromination is significantly more selective towards tertiary carbons. This is over simplified in your explanation.


james May 16, 2013 at 12:39 pm

Thank you for adding this comment, you are correct that there are different selectivities of different types of C-H bonds.


Saaj June 5, 2013 at 10:18 am

You, sir, are amazing!


Jason Mathias March 20, 2014 at 4:13 pm

Odd series of questions, but what would happen to other functional groups if I did this reaction? For instance, if I have but-2-ene or -yne and threw in Cl2 and light, would the Cls simply do chlorination of the alkene/yne? If I have a Carboxylic acid attached to a 3-carbon chain, would this result in the alpha hydrogen being replaced with a Cl?


Yeon Woo Kim November 16, 2015 at 9:26 pm

“…so the product mixture will be 3:1 favoring 1-chlorobutane over 2-chlorobutane.”
Where is the example? Sorry, I do not see it as one of those. Did you mean Propane?


James November 23, 2015 at 4:06 pm

Thanks for pointing this out – fixed. It refers to propane.


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