11.15 Preparation of Alkenylbenzenes
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11.15 11.15 Preparation of Preparation of Alkenylbenzenes Alkenylbenzenes dehydrogenation dehydrogenation dehydration dehydration dehydrohalogenation dehydrohalogenation
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11.15 Preparation of Alkenylbenzenes. dehydrogenation dehydration dehydrohalogenation. CH 2 CH 3. CH. CH 2. Dehydrogenation. industrial preparation of styrene 11,800,000,000 lbs. produced in U.S. in 1999. 630°C. ZnO. + H 2. Cl. Cl. CH. CHCH 3. CH 2. OH. - PowerPoint PPT Presentation
Transcript of 11.15 Preparation of Alkenylbenzenes
11.1511.15
Preparation of AlkenylbenzenesPreparation of Alkenylbenzenes
dehydrogenationdehydrogenation
dehydrationdehydration
dehydrohalogenationdehydrohalogenation
industrial preparation of styreneindustrial preparation of styrene
11,800,000,000 lbs. produced in U.S. in 1999.11,800,000,000 lbs. produced in U.S. in 1999.
DehydrogenationDehydrogenation
CHCH22CHCH33630°C630°C
ZnOZnO
CHCH22CHCH
+ H+ H22
Acid-Catalyzed Dehydration of Acid-Catalyzed Dehydration of Benzylic AlcoholsBenzylic Alcohols
KHSOKHSO44
heatheat
(80-82%)(80-82%)
CHCH22CHCHCHCHCHCH33
OHOH
ClCl ClCl
++ HH22OO
Acid-Catalyzed Dehydration of Acid-Catalyzed Dehydration of Benzylic AlcoholsBenzylic Alcohols
KHSOKHSO44
heatheat(80-82%)(80-82%)
CHCH22CHCHCHCHCHCH33
OHOH
ClCl ClCl
CHCHCHCH33
ClCl
++
DehydrohalogenationDehydrohalogenation
NaOCHNaOCH22CHCH33 ethanol, 50°Cethanol, 50°C
(99%)(99%)
HH33CC CHCH22CHCHCHCH33
BrBr
CHCHHH33CC
CHCHCHCH33
hydrogenationhydrogenation
halogenationhalogenation
addition of hydrogen halidesaddition of hydrogen halides
11.1611.16Addition Reactions of AlkenylbenzenesAddition Reactions of Alkenylbenzenes
HydrogenationHydrogenation
HH22
PtPt
(92%)(92%)
BrBr
CC
CHCH33
CHCHCHCH33
BrBr
CHCHCHCH22CHCH33
CHCH33
HalogenationHalogenation
CHCH22CHCH
BrBr22
CHCH22CHCH
BrBrBrBr
(82%)(82%)
Addition of Hydrogen HalidesAddition of Hydrogen Halides
HClHCl
(75-84%)(75-84%)
ClCl
Addition of Hydrogen HalidesAddition of Hydrogen Halides
HClHCl
via benzylic carbocationvia benzylic carbocation
ClCl
++
Free-Radical Addition of HBrFree-Radical Addition of HBr
CHCH22CHCH
CHCH22CHCH22BrBrHBrHBr
peroxidesperoxides
Free-Radical Addition of HBrFree-Radical Addition of HBr
CHCH22CHCH
CHCH22CHCH22BrBrHBrHBr
peroxidesperoxides
via benzylic radicalvia benzylic radical
CHCH22BrBrCHCH••
11.1711.17Polymerization of StyrenePolymerization of Styrene
Polymerization of StyrenePolymerization of Styrene
HH22CC CHCHCC66HH55
CHCH22 CHCH
CC66HH55
CHCH22 CHCH
CC66HH55
CHCH22 CHCH
CC66HH55
polystyrenepolystyrene
MechanismMechanism
RORO•••• ••••
HH22CC CHCHCC66HH55
••
MechanismMechanism
HH22CC CHCHCC66HH55
RORO•••• ••••
••
MechanismMechanism
HH22CC CHCHCC66HH55
RORO•••• ••••
HH22CC CHCHCC66HH55
••
MechanismMechanism
HH22CC CHCHCC66HH55
RORO•••• ••••
HH22CC CHCHCC66HH55
••
MechanismMechanism
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
RORO•••• ••••
••
MechanismMechanism
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
RORO•••• ••••
HH22CC CHCHCC66HH55
••
MechanismMechanism
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
RORO•••• ••••
HH22CC CHCHCC66HH55
••
MechanismMechanism
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
RORO•••• ••••
••
MechanismMechanism
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
RORO•••• ••••
••
MechanismMechanism
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
HH22CC CHCHCC66HH55
RORO•••• ••••
••
