(Stranger)
07-07-03 07:30
No 445123
(Rated as: good read)
As I was getting ready for a MM wacker and reading some more about it I ran into a post to this US patent
Patent US3475461
Exemple 5 seems amazing, easy,fast, and high yielding
Basically, 25ml 1-octene with 25 ml methanol are charged in a glass reactor. 1millimol (0.178g) PdCl2 and 5 millimole Cupric Chloride dihydrate(.853g) are added, the reactor is pressurized to 3 atm with O2 at 50 degrees Celsius and shaken for 120 minutes. The products were analysed by gas chromatography. A similar reaction was run in parallel, except this time 1% v/v p-cresol was added before the oxidation. The difference in yeild is simply amazing:
No cresol: 49.6% conversion, with 96.8% being 2 octanone
With Cresol: 81.4% conversion, 98.5% being the 2-octanone.
A 80% yield in 2 hours!
25 ml of 1-octene(density 0.715g/ml) means about 18 grams, having a MW of 112.22 that means 0.16 mol octene
0.16 mol of octene only using 1 mmol of PdCl2(0.178).
That means that using 1.78g PdCl2 we could process 1.6 mol safrole! In just under two hours.
I think its worth looking at, especially for those having experience with O2 wackers.
Anyone tried yet? I'm sure its worth looking into
(Hive Addict)
07-08-03 00:57
No 445357
every single one (of many) O2 wacker experiments ended in abject misery.
pssssst: performic, the benzo wacker works fine too.
Eh? ma faut n'exist pas.
(Hive Addict)
07-08-03 10:00
No 445519
reagents, you never really know about chemistry until you begin to practice it.
(Stranger)
07-08-03 15:35
No 445590
with O2 wacker's, I know people like pupillage do.
I agree with u on this. I would try it on a 100g of safrole scale, with a 2L pop bottle.
A 30% increase in yield with no more work, isnt that a charm?
Now I'm not saying the yield would be the same with saf
I tend to think that maybe steric hindrance would slow things down using saf instead 1-octene. The Palladium has to coordinate over the double bond, maybe the benzene ring has a role in that.
But still 80% in 2 hours, thats a quick reaction, and you probably still can recuperate a big part of the used palladium/cupric chloride. Thats of course in the perfect world