Rhodium
(Chief Bee)
10-31-03 21:07
No 468021
       Styrene Derivatives by Aromatic Chloroalkylation
(Rated as: excellent) 		    



Chloroalkylation of Phenol Ethers & Synthesis of Methoxystyrenes (Part 1)
Raymond Quelet
Bull. Soc. Chim. France 196-205 (1940) (../rhodium/pdf /chloroalkylation1.pdf)

Chloroalkylation of Phenol Ethers & Synthesis of Methoxystyrenes (Part 2)
Raymond Quelet
Bull. Soc. Chim. France 205-215 (1940) (../rhodium/pdf /chloroalkylation2.pdf) 		 
 
 
 
    imp
(Newbee)
10-31-03 21:15
No 468023
       Thanks so much     

Thank you Rhodium.

So, what do you think about 1,2-methylenedioxybenzene to isosafrole?? SWIM is curious to hear your opinion.

Maybe that Friedel-Crafts reagent is going to cause some cleavage. Also, the yield would be quite low unless we can make some 'improvisations' to the reaction. 		 
 
 
 
    Rhodium
(Chief Bee)
10-31-03 21:26
No 468026
       Well worth a try!     

It's possible... If the MD ring cleavage would be too great, then one could just switch to a milder Lewis Acid like TiCl4 and try again. 		 
 
 
 
    ning
(Hive Bee)
11-03-03 22:18
No 468542
       if its easy to de-hydrochlorinate that sucker...     

Then the supported-ZnCl2 direct allylation method just got even easier, by removing the need for the supported Na2CO3! Grrrrreat! 		 
 
 
 
    imp
(Newbee)
11-04-03 00:04
No 468565
       Well...     

SWIM sees a couple of obstacles...

1. The paper by Quelet says that dehydrochlorination is done using pyridine. If we had pyridine in the first place, then eugenol --> safrole would be a much better idea.

2. We need to buy/make 1-propanal.

Once SWIM saw the dreaded 'p' word (pyridine) in the article, her/his heart just dropped frown. Is there any other way to dehydrohalogenate that chloropropyl group? 		 
 
 
 
    Rhodium
(Chief Bee)
11-04-03 00:09
No 468568
       Dehydrohalogenation with KOtBu     

This works, but will instead yield propenylbenzene: ../rhodium /allylbenzene.html