Benzene Reaction Chemistry Flashcards
What reagents?
Tuolene –> Benzoic Acid
Na2Cr2O7
—————>
H2SO4 and H2O
What reagents?
Propyl Benzene –> Benzoic Acid
Na2Cr2O7
—————>
H2SO4 and H2O
What is the product?
Tert-butyl Benzene + Na2Cr2O7
no reaction will occur. There is no H available to pluck
What is the product?
Tuolene + NBS
——>
H2O
Bromine installed at benzylic position
What is the reagent?
isopropyl benzene –> acetophenone
- O3
—>
DMS
What reagents?
Benzene to Bromobenzene
Br2 + FeBr3
show mechanism
What reagents?
Benzene to chlorobenzene
Cl2 + AlCl3
show mechanism
What reagents?
Benzene to nitro benzene
HNO3
—–>
H2SO4
What reagents?
Benzene to Iodobenzene
I2
—->
HNO3
What reagents?
Nitro benzene to benzene w/ NH2
Zn
—->
HCl
What reagents?
Amino benzene to nitro benzene
CF3CO=OOO-H
*not sure if this is right dog
What reagents?
Benzene to 1,4-cyclohexadiene
Na/NH3
——>
EtOH
(If EWG present, remove that double bond. If it’s EDG, remove some other bond)
What reagents?
Benzene to benzene sulfonic acid
SO3, H2SO4
What reagents???
Benzene to tuolene?
*Find it in the book way
What reagents?
Benzene sulfonic acid to benzene
H+, H2O
Name the most used EDG’s for benzene and state their conformation of choice. Are they activators or deactivators?
- -O–R
- -N–R2
they favor Ortho and Para
they are activators, they have lone pair electrons at the benzylic position; exception w/ halogens(*faster w/ benzene)
Name the most used EWG’s for benzene and state their conformation of choice. Are they activators or deactivators?
- NO2
- SO3H
- CN
- ketones, aldehydes, esters, carb acids, +NR3
they favor the meta position
they are deactivators, do not have lone pairs at benzylic position; exception w/ halogens (faster w/ benzene)
What are halogens classified for benzene reactions? (O/P or Meta; activator or deactivator)
- O/P
- deactivator
If you are adding a group to an already disubstituted benzene, what thought process is used?
- try to please each group present (O/P or M)
- if there is a tie, the activator will dictate the reaction location
What reagents?
Benzene to R–Benzene
Friedal-crafts alkylation:
R–Cl, AlCl3
—–>
show mechanism
*beware r/a
What are problems with a friedal crafts reaction? (R–cl, AlCl3)
- doesn’t work with deactivated benzenes
- r/a
- the product is activated
What reagents?
Benzene to acetophenone
H3C-C=OCl, AlCl3
—————->
draw mechanism
Draw mechanism for bromination of benzene
- Br2 bonds to FeBr3
- benzene bond attacks and steals a Br
- a Br from FeBr4 attacks H to neutralize charge and reform double bond on benzene
- overall forms FeBr3 and HBr
Draw mechanism for friedal-crafts alkylation reaction
- alkyl halide bond attacks AlCl3 and becomes a carbocation
- benzene bond attacks carbocation site
- AlCl4 attacks H to neutralize charge and reform double bond on benzene
Draw mechanism for friedal-crafts acylation reaction
retro step: carboxylic acid is converted to acyl chloride via SOCl2
- Cl bond attacks AlCl3, forming –C trip O (-)
- Benzene bond attacks C, pushing one of triple bonds to O
- AlCl4 attacks H to neutralize charge and reform double and on benzene
What reagents?
ketobenzene to ethyl benzene
Zn (Hg)
———>
HCl (aq)
Draw mechanism for 6-bromonitrobenzene + NaOCH3
- because there is a EWG, the -OCH3 group will attack the same carbon where Bromine is
- the near bond will then collapse to NO2
- the collapsed bond will then move to its original position, pushing the bromine out
Draw mechanism for benzyne formation when 6-bromotoluene reacts w/ NaOH
- the OH functions as a base, and deprotonates the alpha carbon, which simultaneously pushes its bond onto an alkene
- O-H may then nucleophilically attack either side of the alkyne
- the side not attacked has lone pair electrons the now seek out an H to protonate back
Describe the Mclafferty r/a
carbonyl attacks neighboring H when it is split the alpha H then collapses toward the carbonyl
What product?
6-bromoNitrobenzene + NaOCH3
Benzene with OCH3 installed at bromine position (replacing br)
*must have EWG O/P to bromine
