Menu Icon Search
Close Search

About the ads

Oxidizing Alkyl substituents on Benzene (-1 C?)

Discussion in 'DAT Discussions' started by bchang57, 02.17.12.


  1. Thanks to Crack the DAT

    Thanks to DAT Destroyer
  1. bchang57

    bchang57

    Joined:
    06.13.09
    Messages:
    59
    Status:
    Pre-Dental
    SDN 2+ Year Member

    SDN Members don't see this ad. (About Ads)
    According to DAT Achiever, a benzene ring with an ethyl at C-1, and a methyl at C-4 undergoes oxidation with NaCr2O7, H+, and heat to yield a benzene ring with 2 COOH groups at the 1 and 4 position.

    I thought the methyl would become COOH and the ethyl would become CH2COOH.

    Does someone know the reason as to why the ethyl group loses a carbon?
  2. Msmouth

    Msmouth

    Joined:
    08.13.10
    Messages:
    868
    Location:
    Earth
    Status:
    Dental Student
    SDN 2+ Year Member
    The COOH goes on the benzylic carbon (closest to the ring) every time, and it doesn't matter how long the chain is.
  3. Dotoday

    Dotoday

    Joined:
    05.27.07
    Messages:
    1,569
    SDN 7+ Year Member
    This is a side chain oxidation reaction. Whenever you have a benzylic carbon with a benzylic hydrogen, it gets oxidized to cooh using Group 1 metal with MnO4 or K2Cr2O7. Hope this helps.

    Sent from my MB855 using Tapatalk
  4. bchang57

    bchang57

    Joined:
    06.13.09
    Messages:
    59
    Status:
    Pre-Dental
    SDN 2+ Year Member
    ahh im still lost as to why the ethyl becomes COOH instead of CH2COOH
  5. Msmouth

    Msmouth

    Joined:
    08.13.10
    Messages:
    868
    Location:
    Earth
    Status:
    Dental Student
    SDN 2+ Year Member
    The benzyllic carbon is the carbon closest to the benzene ring......no matter how long the chain is, the COOH will be 1 away from benzene and the rest will disappear.
  6. Dotoday

    Dotoday

    Joined:
    05.27.07
    Messages:
    1,569
    SDN 7+ Year Member
    Yes. It is like a tree branch that has little branches. Once you cut the big branch off, all the little branches will go with it.

    Sent from my MB855 using Tapatalk

// Share //

Style: SDN Universal