E2P2

Question 1

electrophilic aromatic substitutions
-what undergoes this?
-what is an electrophilic?

Answer 1

-benzenes undergo this, a slow substitution reaction where the ring doesn’t break apart
-is a positive species that attacks the aromatic ring by replaces one or more hydrogens

Question 2

mechanism for electrophilic aromatic substitution

Answer 2

benzene + E+
——-><——
benzene with disturbed double, dotted bonds on lower half of benzene (except where E is replacing H)

-H+
——>
benzene with alternating doubly bonds and E

Question 3

halogenation for benzene

Answer 3

benzene + X2

FeX3
——>

benzene with X + HX

Question 4

nitration for benzene

Answer 4

benzene + HNO3 or HONO2

H2SO4
———->

benzene with NO2 + HOH

Question 5

sulfonation

Answer 5

benzene + SO3

H2SO4
———>

benzene with SO3H (benzene sulfonic acid)

Question 6

alkylation
-what does Friedel-Crafts reaction state?

Answer 6

Friedel-Crafts Reaction: the attachment is where the Cl was on the reactant

benzene + R-Cl

AlCl3 (may see Fe)
——->

benzene with R group + HCl

Question 7

acylation

Answer 7

friedel-crafts applies

                     O
                    || benzene + Cl-C-R

AlCl3
——–>
CH2Cl2

benzene with c-r and double bond O attached + HCl

Question 8

hydroxylation

Answer 8

benzene + OH-

—–>

benzene with OH

Question 9

ortho, para and meta only applies to

Answer 9

benzenes with TWO substituent groups

Question 10

groups which are already on the aromatic ring will…

Answer 10

direct the incoming electrophilic either to add the ortho-para or meta position

Question 11

ortho-para directors:
-are what kind of electrons?
-they are groups that contain?
-how many product will it make?

Answer 11

-donating groups (EDG)
-contain lone pairs of electrons
-two benzene products (one ortho, one para)

Question 12

meta directors:
-are what kind of electron group?
-what are EWG groups containing of?
-how many products will be produced?

Answer 12

-withdrawing groups (EWG)
-contain double bonds (other than phenyl) , coordinate covalent bonds , and positive charge groups
-one product

Question 13

ortho-para directors

Answer 13

-alkyl groups
-halogens
-OH
-alkoxy , O-R
-amino groups , NR2 , NHR , NH2
-phenyl

Question 14

meta directors

Answer 14

-CN or C triple bonded to N
-carbonyl groups , C double bonded to O
-nitro groups , NO2
-SO3H
-quaternary ammonium salts , N+R3 , nitrogen with4 bonds and a + charge

Question 15

SO3H is what kind of director?

Answer 15

meta

Question 16

N+R3 is what kind of director

Answer 16

meta

Question 17

alkoxy , O-R , O-CH3 , O-CH2CH3 is what kind of director

Answer 17

ortho, para

Question 18

NR2 , NHR , NH2 (amino groups) are what kind of director?

Answer 18

ortho, para

Question 19

NO2 (nitro groups) are what kind of director?

Answer 19

meta

Question 20

OH is what kind of director

Answer 20

o,p

Question 21

phenyl is what kind of director

Answer 21

o,p

Question 22

carbonyl groups (c double bonded to o) is what kind of director?

Answer 22

meta

Question 23

C tripled bonded to N (CN) is what kind of director?

Answer 23

meta

Question 24

halogens are what kind of director?

Answer 24

o,p

Question 25

alkyl groups are what kind of director?

Answer 25

o,p

Question 26

steps for synthesis of a benzene

Answer 26

1. work your way backwards 2. draw 3 benzenes 3. have 1 and 2 have an arrow and a + 4. the last benzene should be the one given from the compound name 5. find directors from last benzene 6. work backwards and fill in reactions

Question 27

naphthalene

Answer 27

two fused benzene first ring: L3 second ring: R2

Question 28

anthracene

Answer 28

three fused rings 1st: L2 2nd: L3 3rd: R2

Question 29

phenanthrene

Answer 29

has 3 fused rings except the third one is tilted up 1st ring: R3 2nd: R2 3rd: R2

Question 30

aromaticity

Answer 30

4n+2 rule -each double bond equals 2 -aromatic if it's a whole number -anti aromatic if it's not -applies to conjugated benzenes