Chem. Test CH 17

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Chem. Test CH 17
2011-04-03 01:39:28
chemistry test chapter

Notes for CH 17 in progress
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  1. Electrophilic aromatic substitution:
    Step one
    attack on the electrophile by benzene makes sigma complex. show.
  2. Electrophilic aromatic substitution
    Step two
    Loss of proton regains aromacity giving product.
  3. Bromination of benzene
    • Br is not electrophilic enough to react with benzene. So catalyst needed.
    • Makes the Br react more like Br+
    • and also, FeBr4- complex acts like weak base to remove proton from complex.
  4. Formation of sigma complex is strongly ___thermic.
  5. Benzene is _____ as reactive as ______.
    • not
    • alkenes
  6. Chlorination of Benzene.
    Like Bromination, but instead of ___ you use ___.
    • FeBr3
    • AlCl3
  7. Iodination of benzene.
    Instead of a catylist, this reaction requires an acidic oxidizing agent. Which is?
    The I+ electrophile used results from oxidation of ___ by ___.
    • HNO3
    • iodine
    • nitric acid
  8. Show oxidation of Iodine
    H+ + HNO3 + 1/2 I2 ---> I+ + NO2 +H2O
  9. Benzene + ___ Nitrobenzene
    • HNO3
    • H2SO4
  10. Mechanism behuind Nitrification (word?/+of NO2) of Benzene
    Pre reaction: have to form electrophile... show
  11. Describe steps 1 and 2 of nitration of benzene after NO2+ is produced
    • End up with -O-N=O attached at the N
    • reacts just like bromination etc. HSO4- pulls the extra proton off.
  12. Nitrobenzene
    + what ? gives a aniline
    and what does an aniline look like?
    Zn, Sn, or Fe in aq HCl

    • aniline:
  13. Sulfonation of benzene
    Start with benzene and ? --?--> ?
    • SO3
    • H2SO4 takes away extra proton
    • after it has it's extra proton, gives it to the -O that is now attached to molecule. thus you have this
  14. You can undo Sulfonation of benzene with
    benzene sulfonic acid + ? + ? + ? to get
    benzene, H3O+, and ?
    • H2O
    • Heat
    • Acid
    • HSO4+

    can use this to force Cl etc on ortho position
  15. Toluene reacts ___ x faster than benzene
    because Activated
    Methyl group of toluene is an ____, ____=director
    • 25
    • ortho, para
  16. Deuterium in heavy water with benzene
    D2SO4 used instead
    D3O+will continue if have enough to replace all
  17. Put in order from strongest activating group to weakest
  18. What is added to the reaction of aniline (benzene with NH2) so that when you add Br2 and H2O the HBr produced will not protonate the NH2?
  19. If the atom attached to the benzene ring is positive at all, it will be a _______
    meta director
  20. Example of slightly positive atom attached to benzene causing it to be a _____ is what?
    • meta director
  21. NO2 is an example of a deactivating, meta-directing substituent. it requires --?--?--?> to be nitrated (add another NO2 group)
    • HNO3
    • heat (100C)
    • H2SO4
  22. How does NO2 deactivate the ring?
    It has a positive charge. Withdrawing electrongs from the ring. Less negative to react with electrophile.
  23. Some meta directors,
    Weird one, trimethylanilinium iodide
  24. Halogens are _____ but ____ ____ directing
    • electronegative
    • ortho, para
  25. ____ groups are ususally stronger than ____ groups
    • activating
    • deactivating
  26. The Friedel-Crafts Alkylation
    define / describe briefly
    In the presence of a lewis acids such as AlCl3 and FeCl3, alkyl halides alkylate benzene to give alkylbenzenes.
  27. Friedel-Crafts alkylation
    Benzene + ___ --?-->
    • R-X
    • Lewis acid (AlCl3, FeBr3, etc)
  28. Mechanism behind Friedel-Crafts Alkylation
    Formaton of carbocation
  29. Mechanism of Friedel-Crafts Alkylation
    .... next steps
    • electrophilic attack forms sigma complex.
    • and Cl from AlCl4- removes proton giving
  30. In primary alkyl halides, the Friedel-Crafts alkylation mechanism....
    • it just forms a complex with a partial positive charge on the primary
    • carbon in which case they Do bond, and the others just get "kicked off"
    • then it procedes to remove proton.
  31. Acyl Group
  32. Acyl groups named by dropping e and adding __

    • ex. methanoyl
    • ethanoyl
    • propanoyl
    • benzoyl
  33. in Friedel-Craft acylation, can use an acyl group with X and ____ in ____ to substitute in the acyl group
    • AlCl3
    • H2O
  34. Compare
    alkylation v. acylation
    3 things
    Alkylation: 1. cannot work with strongly deactivated derivatives. 2. may rearrange. 3. Polyalkylation is a problem

    Acylation: 1. cannot work with strongly deactivated derivatives. 2. resonance-stabilized acylium ions don't rearrange. 3. formation of deactivated acylbenzene does not react further
  35. Clemmensen Reduction: Synthesis of Alkylbenzenes
    Use ____ to make an __1__benzene
    Then reduce to ____benzene using this reduction
    What do you add to the 1 ?
    • Friedel-Crafts
    • acyl-
    • alkyl-
    • HCl (aq) & Zn(Hg) (or Sn apparently)
  36. The Clemmensen REduction takes the =___
    of the acylbenzene, and makes it two __
    • O
    • H's
  37. CO + HCl
    if you put it under ____
    you will get ___
    • Pressure
  38. Gatterman-Koch formylation: Synthesis of Benzalkehydes

    the necesary ingredients for formyl chloride __ and ___ along with ___ and ____ to give you the needed formyl cation
    • CO & HCl
    • AlCl3 / CuCl
  39. Formyl group
  40. Nucleophilic Aromatic Substitution
    Have to have electron withdrawing (____ in the example)
    React with either ____ or ____
    at ___ degrees C
    • NO2
    • NaOH or CH3NH2
    • 100
  41. In the addition elimination mechanism of nucleophilic aromatic substitution,
    both the Cl and the OH are on the ring simultaneously forming a stable ______
    sigma complex
  42. After the nucleophile attacks the ring, the leaving group get's ______
    knocked off!!
  43. in nucleophilic aromatic substitution
    has to have ______ groups in the ___ or ____ postition in order to stabalize the intermediate.
    • strong electron withdrawing groups
    • ortho , para
  44. Side-Chain reaction
    Permanganate oxidation
    ____ gives nearest ___ extra stability
    • aromatic ring
    • carbon atom
  45. Side-chain reaction
    Permanganate oxidation
    Toulene --?,?,?--> ---?--> Benzoic acid
    • KMnO4, H2O, NaOH
    • H+
  46. In the side chain reaction of Permanganate oxidation the C has to have a ___ on it
  47. Side chain reactions
    replacing a hydrogen attached to a carbon with an X
    involves a ____
    X. draws off an ____ , add ___ ,
    can do again!
    need light
    • carbon radical
    • electron
    • HCl
    • X2
  48. In the side chain halogenation, sometimes the ___ carbon will also gain a halide
  49. the chlorine radicals are more reactive than the bromide ones
    bromination is _____ than ____
    so bromide will not react with the __ carbon
    • more selective
    • chlorination
    • beta
  50. In side chain halogenation with Br, you could also use ___
  51. NBS