liftedresearch - 4-2-2016 at 14:40
Hello all,
I have looked far and wide for a synthesis of alpha Ethyl styrene, but to no avail. I'm not looking to be spoon fed, just to be pointed in the right
direction, and help at all would be greatly appreciated. Thanks in advance
MeshPL - 5-2-2016 at 12:35
That's tricky. Could you please list all reagents that are available to you? I have some ideas, the "simplest" (few steps but unusual, hard to come by
reagents) one is:
Benzene + Propionyl chloride -AlCl3-> Propiophenone
Propiophenone + Tebbe's reagent/Appropraiate Wittig reagent/Petasis Reagent/TiCl4 + Nysted reagent -> Alpha-ethylstyrene
(The latter can be done in numerous ways, there is a wide choice of reagents, none of which have any use for an amateur
)
[Edited on 5-2-2016 by MeshPL]
PHILOU Zrealone - 6-2-2016 at 04:06
Benzene + CH3-CH2-CHCl-CH2OH + AlCl3 --> C6H5-CH(-CH2OH)(-CH2-CH3)
C6H5-CH(-CH2OH)(-CH2-CH3) -acid dehydration like H2SO4 or formic acid/heat-> C6H5-C(-CH2-CH3)(=CH2)
CuReUS - 6-2-2016 at 05:26
you could make this compound in two ways
method 1
acetophenone to the 2-phenylbutan-2-ol
(a) using grignard ( 95 % yield) - Zong, Hua; Huang, Huayin; Liu, Junfeng; Bian, Guangling; Song, Ling Journal of Organic Chemistry, 2012 , vol. 77, #
10 p. 4645 - 4652
(b) using lithium reagent( 92 %)-Imamoto, Tsuneo; Kusumoto, Tetsuo; Yokoyama, Masataka Journal of the Chemical Society, Chemical Communications, 1982
, # 18 p. 1042 - 1044
2-phenylbutan-2-ol to alpha ethylstyrene (83 %) - http://www.tandfonline.com/doi/abs/10.1080/00397910008087423
method 2
phenylacetylene to alpha ethylstyrene( 98%) -http://onlinelibrary.wiley.com/doi/10.1002/recl.19811000305/...
but I found something funny, there is a discussion for the synthesis of alpha ethylstyrene on the Hive
http://chemistry.mdma.ch/hiveboard/chemistrydiscourse/000363...
[Edited on 6-2-2016 by CuReUS]
MeshPL - 6-2-2016 at 11:54
Dehydration of 2-phenylbutan-2-ol will MOSTLY yield 2-phenylbut-2-ene. That's due to stability of internal vs. terminal alkene.
Philou's Friedel-Crafts alkylation may be a better idea. Although 2-chlorobutan-1-ol may be hard to make, it is sure easier to come by than weird
reagents I mentioned.
[Edited on 6-2-2016 by MeshPL]
CuReUS - 7-2-2016 at 06:35
if you are going by the grignard route,you could also react phenylMgBr with MEK to get the tertiary alcohol
meshPL , the paper said that you would get the terminal alkene not internal,even in philou's method,what's stopping the double bond from resonating
from terminal to internal after the dehydration step ?
MeshPL - 7-2-2016 at 22:09
Sorry, my bad. Although I can't view the paper anyway, for some reason. Weird, that in that case more stable alkene is terminal.
chemrox - 8-2-2016 at 16:15
I have some somewhere if you want to buy a few ml...