mcat organic chemistry aromatic compounds chapter 6
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- aromatic is any ________ system
- unusually stable ring
- aromatics are cyclic, ________ polyenes that have 4n +2 pi electr
- conjugated
- aliphatic are all compounds that?
- are not aromatic
-
t or f
aromatic comp need to be planar - t
- huckels rule
-
4n+2 Pi electrons
n can be any nonneg integ -
t or f
neutr comp, anions, and cations can all be aromatic - t
- antiaromatic is a?
-
cyclic conjug polyene that has 4n electr.
its destabl - a cyclic conj polyene that has 4n elect is?
- destabilized
- toluene is?
- a benzene ring with ch3 attached
- phenol is
- a benzene ring with an oh gr
- aniline is?
- benzene with NH2 attached
- anisole is?
- benzene with OCH3 attach
- benzene with OCH3 attach is?
- anisole
- benzene with CH3 attach is?
- toluene
- aromatic compd are called?
- aryl, or arenes
- Ar represents?
- aromatic comp
- aliphatic comp are called?
- alkyl
- aliphatic comp are repres by?
- R
- when the benzene gr is a subst its called?
- phenyl group
- a toluent molec subst at methyl posit is?
- benzyl
- benzyl refers to?
- a toluene molec subst at methyl posit
-
susbst benzene rings
1,2 disubst is called? - ortho
-
benezene
1,3 disubst is called - meta, m
-
benzene
1,4 disubst comp is called? - para,p
- name 4 examples of polycyclic and heterocyclic aromatic compd
-
napthalene
anthracene
pyridine
pyrrole -
pyridine
the nonbond electr pair of the n is in a nitrog __________ orbital - sp2
-
pyridine
the nonbond electr pair of the N is in an sp2 orbital that is oriented how ? - perp to the p orbitals around the ring and is not involv in the conjug pi system
-
pyridine is
acidic
basic - pyrid is basic
-
T or F
pyrrole is acidic - T
-
Pyrrole
the lone pair onthe pyrrole nitrogen is locked into? - ring struct
-
T or F
the phys prop of arom comp are simil to oth hydrocarbons - t
- aromaticity greatly affects the ____________ prop
- chemic
-
benzene
the rings six pi orbit overlap to ? - delocal the electr density
-
benzene
all six c are ______________ hybridized - sp2
- the delocal electrons form a
- "pi electr cloud"
-
benzene
the pi electr clouds are locat? - above and below the ring
- benzene is relativ?
- unreact
- most imp react of aromatic comp is?
- electroph aromatic subst
-
electr aromatic subst
an electrophile replaces a? - proton to prod a subst aromatic compd
- most common examples of electrophilic arom subst?
-
halogenation
sulfonation
nitration
acylation -
electr aromat subst
halogenation
arom ring react with _____________ in presence of __________ -
br, cl
in pres of lewis acid like FeCL3, FeBr3, AlCl3 - Name 3 lewis acids
- FeCl3, FeBr3, AlCl3
- FeCl3, FeBr3, and AlCl3 are all?
- lewis acids
-
Elec ar sub
why is react w fl and I not useful? -
fl - multisubst
I- not react enough, needs spec condit -
elect ar sub
halogenation
react with I needs? - special conditions
-
bezene + Br2 ----> monosubst benzene ring
what are reagents? - FeBr3, heat
-
electr arom subst
Sulfonation
what are reagents? - fuming sulfuric acid (SO3/H2SO4)
- SO3 is?
- sulfor trioxide
- H2SO4 is
- sulfuric acid
-
benzene --------> sulfonic acid
what are reagents? - SO3/H2SO4, heat
-
arom electr subst
sulfonation
end result is a ? - benzene ring with a SO3H on it.
-
ar electr subst
nitration
what are the reagents? - nitric and sulfuric acids
-
nitration
a mixt of nitric and sulfuric acids is used to create? - NO2+
- NO2+ is used in ?
- nitration
-
t or f
NO2+ is a strong ? - electrophile
- benzene with reagents H2SO4 and HNO3 yields?
- a benzene ring with NO2 on it.
- acylation is also called?
- friedel-crafts reactions
- CH3(C=O)Cl is used for?
-
acylation
friedal- crafts reactions - in acylation (friedayl crafts reaction) a __________ in incorportated into the aromatic ring
- acyl group
- what catalyzes the acylation of an arom compound?
- lewis acid
-
t or f
lewis acid like AlCl3 can be used in acylation - t
- friedal crafts acylation and _______________ can occur
- alkylation
- why is friedal crafts alkylation not useful?
- bec the prod are attacked faster than the starting material
-
aromatic
subst effects dep on ? -
gr tends to donate or withdraw electr dens
and how it does so - substit effect what are the 3 categories?
-
1. activat- ortho/para direct
2. deactiv- ortho/para direct
3. deact- meta direct subst -
subst effects
activating ortho/para direct subst are ___________ donating - electron
- NH2, NR2, OH, NHCOR, OR, OCOR, and R are?
- activat, ortho para direct subst
- what subst are activ , ortho/para direct subst?
- NH2, NR2, OH, NHCOR, OR, OCOR, and R.
- activat , ortho/para direct substit are electr?
- donating
- NH2, NR2, OH, NHCOR, OR, OCOR, and R have what kind of subst effect?
- activ, ortho, para
- F,CL, Br, and I do what as subst effect?
- deact, ortho/para direct
-
t or f
f,cl, br, and I are weakly electr withdraw - t
-
subst eff
NH2 is? - activ, ortho/para direct
-
subst eff
what are activ, ortho/para dir subst? - NH2, NR2, OH, NHCOR, OR, OCOR, and R
-
subst eff
NHCOR? - activ, ortho/para direct
- NO2, SO3H, and carbonyl compounds have what subst eff?
-
deact, meta direct
electr withdrawing - what subst are deact, meta direct subst?
- NO2, SO3H, COOH, COOR, COR, and CHO
- CHO has what subst eff?
- deact, meta direct
-
subst eff
activat are ___________ directing - ortho/para
- halogens are exceptions, alth they are e- withdraw and deactiv, they are?
- ortho/para directors
-
toluene
electr arom subst
the methyl gr will direct towards? - ortho/para
- benzene can be reduced by?
-
catalyic hydrogenation w/high press and temp
ruthenium, rhodium on carbon are used. - H2, Rh/C, 100 C will be used for?
- reduction of benzene