03-11-02 04:05
No 280608
Can hydrated ferric chloride be dehydrated (in an oven-- like MgSO4 is dehydrated) to anhydrous ferric chloride, for, say, a Freidel-Crafts alkylation with allylbromide?
(Distinctive Doe)
03-11-02 05:27
No 280627
Heat Won't do it.
This post has two methods in it, but neither uses easily acquired chems.
Post 241314 (foxy2: "Re: TITTIES & a ? about Dehydration of SnCl4.5(H20)", Chemistry Discourse)
Here is the PAYDIRT
You need a powerful vacuum and some DMSO, thats it.
I'll bet a slightly weaker vacuum would work if you left it heating for alot longer. This is pretty.
Patent US3471250
Those who give up essential liberties for temporary safety deserve neither liberty nor safety
(Master Searcher)
03-11-02 07:23
No 280658
Some companies sell anydrous ferric chloride for etching printed circuit boards.
Apparently you can use hydrated ferric chloride in the Friedel-Crafts reaction. See Post 255616 (PolytheneSam: "Re: Substituted P2P's: Would this work?", Novel Discourse)
http://www.geocities.com/dritte123/PSPF.
(Official Hive Translator)
03-11-02 07:35
No 280662
Well, the old 'classical' method by which they prepare unstable (that is, the ones that partially hydrolize on drying - like CuCl2 or FeCl3, not the ones that don't give off water easily, like ZnCl2) metal chlorides is by gentle heating them in stream of dry HCl. You can judge the end of the rxn by the change in color.
Of course, this ain't for kitchen either
, but in a reasonable environment could bee quite manageable.Antoncho
(Official Hive Translator)
03-11-02 07:41
No 280665
Aside from that, dear Julia!
Can you please post at least one Friedel-Crafts allyl bromide procedure either for benzene or a substituted benzene, or both, PLEASE!
I am personally very interested in the subject aswell as a Russian collegue of mine have been f...ing w/this rxn, but had difficulties - for the lack of a good procedure to follow!
If you would, that'd bee greatly appreciated!
Antoncho
(Master Searcher)
03-11-02 07:49
No 280669
I have a journal article somewhere about the Friedel-Crafts reaction with allylchloride and benzene. It says most substituted benzenes give low yields. What about chloroacetone? Post 255180 (neuromodulator: "Substituted P2P's: Would this work?", Novel Discourse)
http://www.geocities.com/dritte123/PSPF.
(Ubiquitous Precursor Medal Winner)
03-11-02 08:27
No 280673
Going just by color alone, I made nickelous chloride in its anhydrous yellow form, by boiling its green solution to dryness.
a half a pints a half a pound a half a world a half a round
Sidearm n. Flask neck tube.
(Official Hive Translator)
03-11-02 10:44
No 280707
heh! That's the point. All heavy metal chlorides are susceptible to this rxn when drying:
MeCln*mH2O ---> MeCln-1(OH) + (m-1)H2O + HCl
... to a certain extent. I agree w/you that it can bee done fairly well w/out any HCl drying with at least NiCl2 and CuCl2 - to both of those i can also attest myself - but still if you dissolve an appreciable q't'ty of your unhydrous salt in water, you'll notice it's somewhat muddy.
Of course, for NiCl2 it doesn't matter at all and for CuCl2 (BTW, you seem to have abandonned that most interesting thread about DMS-whatever - ????) it probably also is so, but i know nothing about FeCl3.
Anyone else have anything to say on Friedel-Crafts allylations???
Antoncho
(Newbee)
03-11-02 11:48
No 280725
yes antoncho,
not about friedel-crafts though. instead of heating in HCl-atmosphere, one can use NH4Cl. so for MgCl2 i know that procedure to work just fine. mix MgCl2*xH20 with excess of NH4Cl (exact amounts dont know this moment) and heat 'till all NH4Cl has gone.
for AlCl3 this method does not apply.
otto
(Her Majesty, Stoni's Kitty)
03-11-02 12:54
No 280771
Photographic supply companies also sell anhydrous ferric chloride. This has already been verified to be true.