Guaranteed Method To Pass Organic Chemistry

On this page you can demo one of our reactions (Free Radical Halogenation) using our unique flashcard format.

Here are some features of this page:

  • Click on any of the windows below to reveal the reactants, product, reaction description and mechanism.
  • You select which elements to reveal to customize your learning.
  • This has proven to be an excellent study method for our students. Read what our students have to say here.
  • We have over 180 organic chemistry reactions that are taught in Organic Chemistry for you to study and each reaction has key study tips that you will want to know for your exams.

When you signup, you will have access to much more than just the reaction flashcard study pages such as the one you see here including Quizzes!

Our Student's Are Top In Their Class!

The best o-chem site out there- hand down. Bravo, Bravo!

Joel M. | University of California San Francisco

All I can say is I wish that I had found this site a month ago. There is no need to research other orgo study resources because this is the one you need.

Brad S. | Yeshiva University

*** Click On Any Window To Reveal ***

Reaction Name

Free Radical Halogenation

Alkyl Halides

Reaction 1 of 116


  • Overall Big Picture: Alkane + Halogen in the presence of heat or light→ Alkyl halide

  • Depicted here is free radical bromonation (the halogen here is Br). However, this can also be accomplished with Cl or I
  • Mechanism Hint: There are three steps to the mechanism in this reaction:
    • Initiation
    • Propagation
    • Termination
  • Key Tip: Free radical stability follows carbocation stability:
    • allylic > tertiary > secondary > primary > methyl
    • Therefore this reaction will want to form the most stable free radical during the propogation step and thus the halogen will appear in the more substituted position. For example, in this reaction, the Br appears on the most substituted carbon in the product.

  • Key Comparison:
    • Free radical bromonation is a slower reaction and depends on the stability of the free radical intermediate.
    • Free radical chloronation is a more rapid reaction and depends not on the stability of the free radical intermediate, but rather on the number of hydrogens present. Therefore, an unreliable mixture of products tends to be formed with free radical chloronation.

Sign Up