09-29-01 01:16
No 218257
This might not be novel, but if applied to other phenols it might be. According to US patent 2490842 anisole can be made from phenol and CH3MSO4 where M can be a metal such as sodium or potassium or it can be NH4. Example 2 uses methyl sodium sulfate to make anisole from phenol. Note also that the patent was assigned to du Pont. Also see US patent 2031719 on condensing phenol and alcohols with ZnCl2.
http://www.geocities.com/dritte123/PSPF.
(Official Hive Translator)
09-29-01 07:01
No 218337
This might not be novel, but if applied to other phenols it might be.
Yes, i posted it (and one more interesting rxn) a while ago - see Post 191179 (Antoncho: "Alkylations of phenols with sodium alkylsulfates", Chemistry Discourse). Didn't get a single fucken reply to it.
Well, at least you know now that someone besides you is interested
Antoncho
(Master Searcher)
09-29-01 18:00
No 218420
Looks like obituary replied, so its not dead yet. Wait a minute, does that make sense?
Yeah, I don't remember your post, Antoncho, and I thought I caught all the important stuff since I look at the hive every day. I recently became interested in these reactions. Dimethyl sulfate is toxic and hazardous (I read things about the fumes being dangerous) and you seem to need SO3 and/or fuming H2SO4 to make, as well as, vacuum distillation. Concentrated H2SO4 might work, but the yields seem to be low. Methyl halides might be an alternative, but methyl bromide boils at ~4 º C, methyl iodide has a higher bp (42.5º C) but iodine is more expensive. So, I looked through class 568 subclasses 628, 630, 648, 654 and 657 on methods of making aryl-alkyl ethers, and class 558 subclasses 20, 21, 38, 39, 40, 41 and 43 for various ways of making alkyl sulfates and alkyl hydrogen sulfates. I have a lot of patents listed which I can sort out and post.
http://www.geocities.com/dritte123/PSPF.
(Official Hive Translator)
09-29-01 19:10
No 218428
I have a lot of patents listed which I can sort out and post.
Oh, please, would you? I'd bee very grateful.
Sincerely Yours,
Antoncho
(Master Searcher)
09-29-01 19:40
No 218431
I'll start out with the patents on alkyl sulfates and alkyl hydrogen sulfates (class 558). Some of them discuss the use of Na2SO4 as a drying agent, too. I finished the areas before 1975 since they're images only (568/654, 657 and 630 complete) and decided to finish the rest by looking at the text on the internet at 56K, later. Here's what I got in my notes so far.
1411215 Na2SO4
2062454 RHSO4 + MCl --> RMSO4 + HCl (M = metal)
2176005 RCaSO4
2688035 use of alkali carbonates
3305578 R(amine)SO4, ie. R(R'NH2)SO4
4146551 Mg salt of RHSO4
3829457 RMSO4 from ROH & SO2 and O2
1599119 ferrous and cuprous catalyst for ethylene
1589372 ethylene catalysts
1574796 ethylene catalysts
1478498 ZnCl2
1484249
1641005 SO2Cl2 & alcohol --> alkyl sulfates
1998411 RMSO4
3024263 2NaHSO4 + C2H5OH = C2H5HSO4 + Na2SO4 + H2O ; Na2SO4 dehydration
3047604 Na2SO4
3232976 interesting aspirator pump apparatus
I didn't find anything on making methylene sulfate. I wonder how it's made assuming it exists. Post 218253 (PolytheneSam: "methylene sulfate", Chemistry Discourse)
http://www.geocities.com/dritte123/PSPF.
(Old P2P Cook)
09-29-01 22:03
No 218454
I didn't find anything on making methylene sulfate. I wonder how it's made assuming it exists.
AFAIK, it doesn't exist.
(Master Searcher)
09-29-01 22:10
No 218457
What does AFAIK stand for and why is it in the patents listed in this post? Post 218253 (PolytheneSam: "methylene sulfate", Chemistry Discourse)
http://www.geocities.com/dritte123/PSPF.
(Hive Addict)
09-29-01 22:31
No 218465
AFAIK= as far as i know
and obit believes that the existence of isolated methylene sulfate has been ruled out already for it's tendency to form methyl sulfate or dimethylsulfate or something like that-
(Old P2P Cook)
09-29-01 22:35
No 218468
AFAIK - As Far As I Know
I was just looking at your post that has those three patents. Of the three, after quickly skimming the text, I was only able to find the mention of methylene sulfate in one of them. I will try looking through the others again when I have more time.
It is interesting that in the one patent where I saw the mention it was as methylene sulfate as a formaldehyde source.
As to why methylene sulfate was mentioned in these patents. Remember that methylene sulfate was not central to any of these patents. Methylene sulfate was likely mentioned just to cover all bases. The thinking might have been like this: "I don't know whether methylene sulfate exists or not but I will mention it just in case so that if it does exist someone would not be able to use methylene sulfate to avoid this patent".
(Stoni's sexual toy)
10-02-01 11:30
No 219416
MSO3-O-Me is formed during the usual DMS methylations. Only one of the DMS methyl groups reacts under regular reaction conditions. Using the second Me means anhydrous reaction conditions.
Back to the topic of the thread:
dialkyl carbonates, phosphoric acid trialkyl esters, toluene sulfonic acid esters etc.
Alkyl halogenides are expensive, dangerous and have low boiling points. Dimethyl carbonate on the other hand is cheap and can be used as a safe DMS substitute, and so can trimethyl phosphate if I remember correctly (also cheap and quite safe). Same goes for the ethyl esters.
(Hive Bee)
10-06-01 10:08
No 220874
Bees,
there has been a post - see Post 71469 (uemura: "trimethyl phosphate", Chemistry Discourse) - by uemura on trimethyl phosphate some time ago.
BTW: Trimethyl phosphate can be made from P2O5 and MeOH.
Carpe Diem
(Master Searcher)
10-07-01 01:59
No 221040
Here's some patents from class 568 subclasses 657, 654, 630 and 648 on aryl-alkyl ethers. I'll just put down what I have in my notes. See the patent for more information.
2052745 refining anethole
2233080 ArOH + RX + MOH --> ArOR + MX + H2O (M = metal)
2516412 syringaldehyde, MeBr for MeO-
797024 CH3Cl
1801901 EtCl
2031719 ZnCl
2070848 RCl
2103736 phospho Mo/W catalyst
2487832 dimethyl ether used to make ArOMe
2490842 M(Me)SO4, (M = metal)
2727926 ØCOOH --> ØOH
3911022 ØOH + ester --> ØOR
5817886 phenol + MeOH + catalyst
4918241 aryl iodides --> phenols
4765455 phenols + alcohols, sulfated oxide of Cr/Mo/mixture catalyst
4675454 phenols + alcohols, sulfated oxide of Cr/Mo/mixture catalyst
4611084 phenols + alcohols, sulfated oxide of Mn/Re/mixture catalyst
4638098 phenols + alcohols, sulfated oxide of Zn/Cd/Hg/mixture catalyst
2067960 hydroquinone + RX in ROH
2235884 hydroquinone + RX in ROH
2439375 3,4-MD-phenyl --Ni--> phenol
2676947 dimethoxystyrene
2694736 Hg and Ni catalyst
2782239 alcohols & catalyst, hydroquinone and alumina-silicate catalyst 550º F
2847477 Hg acetate catalyst
http://www.geocities.com/dritte123/PSPF.
(Master Searcher)
10-19-01 02:40
No 226515
Here's page 3 from British patent 646736. Note in example 2, the use of methyl hydrogen sulfate and NaOH. Webshots automatically resized the image to a smaller size. I could scan all 5 pages and put it in another place so it would have a higher resolution if anyone is interested.
http://www.geocities.com/dritte123/PSPF.
(Master Searcher)
10-19-01 04:50
No 226605
Here's the link to Espacenet.
http://l2.espacenet.com/dips/bnsviewer?C
http://www.geocities.com/dritte123/PSPF.
(Master Searcher)
10-21-01 04:51
No 227371
Can someone translate this.
Here's the English abstract.
http://www.geocities.com/dritte123/PSPF.
(Official Hive Translator)
10-21-01 11:52
No 227445
A method of etherification of phenols is known, in which the ethers are made by reacting phenols w/methanol in presence of acidic catalysts such as methylsulfuric acid (!!) Al2O3, alumosilicates.
For the purpose of simplification it is suggested to carry out this rxn w/an cation-exchange resin catalyst KU-2 (no clue as to what it is). This catalyst is stable and suitable for multiple usage.
Ex. 1 - 0,5 mole C6H5OH, methanol (0,5-2,0 mole) and 23 g of KU-2 are heated at 110 C in a reactor for 10 hours. The liquid products are filtered from the resin and the product is fractionated to get anisole (56% from the initiate amt. of phenol), unreacted phenol and tarry residue (~2%) Yield is 98% based upon the reacted phenol. (that's what these motherfuckers meant by 98% yield
)Ex. 2 - 0,5 mole o-cresol, 0,7-1,2 mole methanol, 23 g KU-2, 11 h at 115 C. Yield 38% to the whole mass of cresol, 96,5% to the reacted, 3% tar.
Well, i guess it's not really suitable for kitchen
... That methylsulfuric part sounds interesting, though.Antoncho
(Master Searcher)
10-21-01 16:10
No 227474
Methyl sulfuric acid sounds like its the same thing as methyl hydrogen sulfate which you get when you mix methanol and sulfuric acid. I don't know how far to the right (of the equation) the reaction goes. If you mix methanol and sulfuric acid you probably get a mixture of methyl hydrogen sulfate, methanol, sulfuric acid and water (from the methanol and sulfuric acid). Maybe I could find the equalibrium constant somewhere. Did you look at that British patent two posts up? Example 2 uses methyl hydrogen sulfate and the anisole is steam distilled out of the mixture. Note that the etherification is done in the presence of water. I'm wondering if it would work if you mixed methanol and sulfuric and let it react to form methyl hydrogen sulfate and then use that without any H2O removal before use. See also US patents 3024263 and 3047604 which discuss ethyl hydrogen sulfate.
http://www.geocities.com/dritte123/PSPF.
(Master Searcher)
10-21-01 18:32
No 227499
OK, another one, Antoncho, please. Here's the English abstract. I'll just post the links to pages 1 and 2 of the patent (USSR No. 141159).
http://wsphotofews.excite.com/001/S0/Q4/
http://wsphotofews.excite.com/017/UX/yI/
http://www.geocities.com/dritte123/PSPF.
(Official Hive Translator)
10-25-01 07:20
No 228577
Sammy!!!
i'm in debt to you for ever, ever-ever!!!
You finally DID it! It is unfuckingbelieveable, but true!
Needless to say, catechol is a sensitive compd and if you can mehylate it w/NaMeSO4 the same method will rather certainly work on hydroquinone and the aldehydes.
I won't translate these russian links since they contain no other info than already posted. They will bee very much appreciated by my fellow russian bees, though. The only thing the english abstract doesn't mention is the prep'n of NaMeSO4: "...265 g of methylsulfuric acid is neutralized w/235-237 g of 42% NaOH soln. with stirring, the temp. should bee around 28 C."
The pure alkylsulfuric acids themselves are very conveniently prepared in almost quantative yield by a method submitted by our dear comrade Foxy2 - the one with EtOH/H2SO4/NaSO4 - see Post 216461 (foxy2: "Ethyl hydrogen sulfate", Chemistry Discourse). There's also a US patent # 3,024,263 found by - guess whom
- our admirable PolytheneSam, naturally, which describes a similar process, but using NaHSO4 (hydrate) and alcohol.SWIM have tried the 1st method and is firmly certain that it works exactly as described. Well, Foxy2 didn't give the exact procedure, just the outline, so SWIM just used his common sence and the info he grasped from the said US patent, so it's not optimized, but anyway here's what he did:
100 cc (2 mole) of 92% H2SO4 were dripped into 100 cc (2.2 mole) of methanol in ice bath w/good stirring. You can skip all this precautions at this stage but you do need to chill the rxn well. The resulting mixtr had a reddish tint. Then in it was dropped 80 g of powdered anhydrous Na2SO4. This is probably an overkill as Na2SO4 forms a decahydrate at below 32 C. Just to bee sure. The mixtr was then heated in boiling water for 10 mins - again just to bee sure (Foxy2's proc. mentioned RT, but in the US patent as well as in the proc. on Rhodium's heating was employed) and cooled to below RT in cold water, with frequent shaking. SWIM left it at RT for some time, periodically giving it a shake, to ensure all the water has been absorbed. It was then vacuum filtered through a paper filter, the Buchner closed w/a lid to exclude atmospheric moisture, and kept in a freezer overnight.
Thus obtained methylsulfuric acid was a viscous off-white liquid with density of 1,32 g/cm3 and amounted to 100 ml (1.2 mole) - much of it left in the filtered sulfate - a good source of vacuum (SWIM's is very bad) and less Na2SO4 probably should bee used to improve the yield.
This acid was dripped with good stirring and chilling in ice bath into a slight molar excess of NaHCO3 in some water - a little more than enough to cover the soda. The mixtr actually thickens as neutralization proceeds. Thus obtained homogenous fine paste was evap'd on a steam bath aided w/a hair dryer - now note this the alkylsulfates (ethyl too) obviously have mp lower than 100 C - at least they will never look dry while hot and solidify upon cooling.
Thus obtained salt was further dryed in exicator for 2-3 days over CaO.
A 5 g sample of the salt was dissolved in a minimum of hot water and reacted w/sat'd CaCl2 soln. The precipitate was filtered, washed, flame-dried to give 1,5 g of CaSO4*1/2H2O which corresponds to NaMeSO4 content of approx. 71% -
!These procedures were also performed with ethanol instead of methanol by a russian bee named Vitsh with whom SWIM worked on this project hand-in-hand. His results were essentially the same except he got his ethylsulfate content only 50% - and Antoncho strongly believes it was because of his inverted neutralization technique - he added sat'd Na2CO3 soln to the acid.
Now this will bee obvious to many but still allow me some notes on the issue of neutralization.
The very clever
authors of the russian patent don't mention if the acid was added to the alkali or backwards. From the precise wording of their phrases Antoncho guesses that they did the latter.Now, it is a well-known fact that alkylsulfuric acid salt are stable, but the acids themselves exist in aq. solutions in equilibrium w/AlkOH/H2SO4, which is about fifty-fifty. This means the following: suppose during neutralization the soln. has become acidic. A molecule of an alkylsulfuric acid hydrolizes to H2SO4 , which, unlike the former, is a two-hydrogen (what's the correct term in English?) acid and reacts with two molecules of NaAlkSO4, producing two molecules of AlkHSO4, which in turn react with four molecules of NaAlkSO4 and so forth - as you see, this rxn proceeds in geometrical progression - that is, FAST - and stops when the equilibrium point (~50%/50%) is reached.
Another empirical data comes from one more experiment of SWIM's - he dripped MeHSO4 into ice-chilled sat'd NaOH taking pH every now and then. SWIM was afraid to have leftover NaOH in his mixtr as nitromethane forms explosive salts with it. So the rxn accidentally got acidic for like not more than 2 mins and - voila! - he got his sulfate content that very 50%.
Oh gosh that's enough for now
Antoncho
(Chief Bee)
10-25-01 11:31
No 228632
The correct english term for a "two-proton acid" is "dibasic acid" afaik.
(Master Searcher)
10-26-01 00:51
No 228809
Antoncho, have a look at that British patent, especially page 3. Post 226605 (PolytheneSam: "Re: ArOR, Alternatives to dimethyl sulfate", Novel Discourse)
http://www.geocities.com/dritte123/PSPF.
(Hive Bee)
10-26-01 03:21
No 228842
yep there's that SO3 arearing its stinky little head again.
oxidize SO2 over catalyst (CU?) and pass directly into H2SO4 and don't drink any. well???
always appreciate your time and consideration
(Master Searcher)
10-28-01 00:50
No 229389
This comes from Experimental Organic Chemistry by J. F. Norris 1933, pages 84-85. I wonder how it would work with methanol.
Preparation of Potassium Ethyl Sulphate (a) Pour into a small flask 20 cc. of ethyl alcohol, and add slowly with constant shaking 10 cc. of concentrated sulphuric acid. Connect the flask with a reflux condenser and heat on a boiling water-bath for one hour. Cool the liquid and pour it slowly into 200 cc. of cold water. The solution contains ethyl sulphuric acid, alcohol, and sulphuric acid. The acids are separated by making use of the fact that barium ethyl sulphate is soluble in water and barium sulphate is insoluble. Add to the solution, with constant stirring, small quantities of barium carbonate1 as long as carbon dioxide is evolved. Filter in a porcelain funnel, and wash the precipitate twice with about 20 cc. of hot water. The filtered solution contains barium ethyl sulphate. Write equations for all the reactions. Test 5 cc. of the solution for barium in the usual way. (Eq.) Test the solutiion for a sulphate. Result? Heat about 5 cc. of the solution with about 1 cc. of dilute hydrochloric acid. (Eq.)
(b)Conversion of barium ethyl sulphate into potassium ethyl sulphate. -- Heat the rest of the solution of barium ethyl sulphate to boiling and add a solution of potassium carbonate until the solution is slightly alkaline. (Eq.) Filter hot, wash the precipitate twice with a small amount of hot water, and evaporate the filtrate to crystallization on a steam bath. When cold, filter off the crystals and wash them with a little cold alcohol; dry on a porous tile. The salt can be recrystallized from boiling alcohol.
1 If barium carbonate is not available, calcium carbonate may be used.
http://www.geocities.com/dritte123/PSPF.
(Master Searcher)
10-28-01 01:47
No 229401
It says in the Merck Index 9th edition under methyl sulfate.
5995. Methyl Sulfate. sulfuric acid monomethyl ester; methylsulfuric acid; methyl hydrogen sulfate; monomethyl sulfate; acid methyl sulfate;.....
from methanol and sulfuric acid: Dumas, Peligot, Ann. 15, 40 (1835).....
Oily liquid: does not solidity at -30º C. d15 1.45-1.47. Freely soluble in water, less soluble in alcohol. Miscible with ether.
See also Dimethyl sulfate.
Barium salt, C2H6BaO8S2, barium methyl sulfate.Dihydrate, efflorescent crystals. Poisonous! Sol. in water, alc.
Calcium salt, C2H6CaO8S2, calcium methyl sulfate, calcium sulfomethylate. Crystals. Soluble in water.
Note that both the barium and calcium salts of methyl hydrogen sulfate are soluble in water. Barium sulfate is practically insoluble in water (1 gram dissolves in 400,000 parts), dilute acids and alcohol. Calcium sulfate is soluble in water (0.2 parts/100 parts at 18º C anhydrous CaSO4). (source: Merck Index 9th edition). In the Handbook of Chemistry and Physics CaSO4 (anhydrous), the hemihydrate (Plaster Paris) and dihydrate are listed. Solubilities in cold water (20-30º C) for each are about 0.2-0.3 g/100 ml water.
http://www.geocities.com/dritte123/PSPF.
(Distinctive Doe)
10-28-01 05:01
No 229446
I wonder if Barium hydroxide can bee used instead of the carbonate? Would it decompose the product?
Do Your Part To Win The War
(Official Hive Translator)
10-28-01 05:55
No 229460
Sam, i'm sorry to say that but this is essentially the same procedure that is sitting at Rh's like for ages
- the problem with it is the filtrations. They are not only - to put it mildly - a major pain in the ass - but also yield-killers.This US patent that you gave me, Sam, - 2,176,005 describes an easy way to avoid this problem.
You could use alkali earth hydroxides as well, at least w/Ca(OH)2 it is a standard way they make it in Russian literature.
The whole point in all this is the fact that one doesn't need pure methylsulfate neither for methylation (as the russian patent suggests) nor for nitroalkane synth - my collegue Vitsh's uncle's third cousin's dog reports a 28% yield (based on ethylsulfate) from 50/50 mixtr w/sulfate.
SWIM tried to pull that Ca procedure (he didn't read that patent at the time though) and he shivers at the very thought of possibly having to repeat it one day.
Antoncho
(Master Searcher)
10-28-01 20:44
No 229624
I remember seeing something posted about it, but when I UedTFSE on Rhodium's site using the keywords sodium, ethyl and sulfate I didn't find it. I think I tried ethyl and sulfate alone, but still didn't find it.
Are you talking about this? ../rhodium /diethyl
That's on diethyl sulfate not salts of monoethyl sulfates.
http://www.geocities.com/dritte123/PSPF.
(Chief Bee)
10-28-01 21:26
No 229633
It's in here: ../rhodium /nitroal
(Master Searcher)
10-28-01 22:05
No 229642
Oh, yeah. Nitroethane from sodium ethyl sulfate. Thanks, Rhodium. Now can anyone find information about the equilibrium constants of methyl hydrogen sulfate and ethyl hydrogen sulfate in water?
MeOH + H2SO4 = MeHSO4 + H2O
EtOH + H2SO4 = EtHSO4 + H2O
http://www.geocities.com/dritte123/PSPF.
(Ubiquitous Precursor Medal Winner)
11-02-01 13:59
No 232101
Sam, I don't have the detailed info you need, but a darn good approximation is: don't put 'em in water. They hydrolyze instantly. That's why drying agents are used in their production, right?
Your correct link above is ../rhodium /diethyl
Gotta get up pretty early in the morning to keep up with Rhodium. He's always upgrading his site.
turning science fact into <<science fiction>>
(Master Searcher)
11-03-01 00:44
No 232302
That link worked when I posted it. Also, I read that alkyl hydrogen sulfates and dialkyl sulfates hydrolyze slowly in water.
http://www.geocities.com/dritte123/PSPF.
(Chief Bee)
11-03-01 01:18
No 232327
They hydrolyze slowly enough to make water a usable reaction solvent for alkylations of phenols.
(Official Hive Translator)
11-17-01 16:30
No 237759
Well guys what would you think – NaMeSO4 methylation (according to SWIM’s astral projection’s memoirs) clearly works on hydroquinone. p-diMeO benzene is distilled out fast - as soon as it forms, as it seems. SWIM ain’t sure of yield though because he had an accident as a result of which… oh well- you all probably know what kind of a chemist he is
The condenser tends to get plugged w/the product crystals, so watch it (and make an “emergency outlet” in the stopper).SWIM will try to re-do it properly and do a write-up, but he has an important question – please, help him.
What if instead of steam-distilling the p-diMeOB, one just poured some toluene on top of the rxn and refluxed it for some time? Actually, the Q is – would the product evaporate appreciably when later distilling off toluene (at atm. pressure)?
SWIM, let alone Antoncho, is totally uneducated in this field
Thanks ahead,
Antoncho
(Chief Bee)
11-17-01 17:35
No 237780
1,4-dimethoxybenzene is a solid at room temp (melts at 40-50°C?) and it will not evaporate readily. However, it has a tendency to sublime even at room temp, but as I understand it, solids cannot sublime as long as they are covered with solvents (the toluene). The general idea I'm trying to convey here is to not heat the product too much after the toluene has evaporated. If it is at all possible, extract the product with a more low-boiling solvent.
(Master Searcher)
11-17-01 17:40
No 237783
Here's some information from the 60th edition of the Handbook of Chemistry and Physics. Hydroquinone dimethyl ether is under benzene, 1,4-dimethoxy- in the 60th edition. Mol. Wt. = 138.17, lf(w) ...., m.p. = 58-60, b.p. = 212.6, 10920, density = 1.0526 at 55º C, slightly soluble in water, soluble in alcohol, very soluble in ether and benzene.
lf(w) means leaflets from water so it looks like you can recrystalize it from water. 10920 means the boiling point is 109º C at 20 mm pressure (212.6 at atmospheric pressure). Since the melting point is 58-60º C maybe you could try an air cooled condenser or use hot water in your condenser. To get all the steam to condense, cool the receiver in an ice bath and use a stopper and/or adaptor between the condenser and receiver. The crystals should form in the receiver. I would just stay with the steam distillation.
http://www.geocities.com/dritte123/PSPF.
(Official Hive Translator)
11-17-01 20:32
No 237809
Thanks for the replies, and i will certainly take advantage of Sam's advice if i decide to go via 'classic' route.
But still there are more questions.
1st of all - diMeOB is a liquid at 110 C, more so, its bp is only a 100 C higher than that. What i meant is - won't it form an azeotrope or some such or just co-evaporate (the way MeOH does w/water) - in this case it may bee ruining.
And the whole point of doing this w/toluene (SWiM does have some low-boiling solvts
) is that rather than steam-distilling it and then doing all that work-up, one would get all his DMB immediately absorbed into the toluene layer, which i believe would remove it faster from the alkaline envir't (thus increasing the yield) as well as simplify whole thing technically - IF and only if toluene could bee boiled off.Would a glass-filled 50 cm fract. column bee of help in this?
What if it was just left to evap. at RT under a fume hood - or will that make for a yet higher DMB sublimation rate?
Or - will p-diMeOB, possibly, fall out of it if chilled to well below zero?
- i know asking questions is easy.Antoncho
(Chief Bee)
11-17-01 21:54
No 237826
I don't know about the sublimation rate, I have seen two containers of dimethoxybenzene, and one had some crystals hanging from the lid, and the other had not. I took that as an indication of that the compound was able to sublime. I have no other proof.
If the boiling points are 100°C apart, you don't need a column. IF you chill the toluene solution, it is possible that some dimethoxybenzene will precipitate, but definitely not all of it.
My suggestion is that you try a small-scale run with the reaction, and then distill off the toluene using the procedure you suggested, and as soon as toluene stops coming over, chill the distillation flask, and you will get your crystalline product. Purification suggestions are either vacuum distillation or recrystallization from something (dunno what).
If sublimation or azeotrope formation (the latter I find unlikely) is a problem, you will notice this by a lower yield, and dimethoxybenzene-smelling toluene in the distilling flask, or dimethoxybenzene crystals forming in the distuillation head/condenser after cooling. But this is no serious problem, as all your product is still left in the distillation apparatus and/or toluene. Try it - any success story goes right on my page.
(Master Searcher)
11-17-01 22:58
No 237839
I remember CHEMMAN saying something about some phenylacetone distilling over with toluene. I think this is the post Post 52419 (CHEMMAN: "Ketone purity", Methods Discourse) . Also I heard of someone distilling off toluene from amphetamine base after extracting it with toluene. After a while the amphetamine base distills over with the toluene. He figured this out by adding H2SO4 (sulfate precipitates) to the toluene which distilled over. He filtered out the ppt. and left the toluene filtrate in a pan to evaporate to get more of the infamous sulfate.
http://www.geocities.com/dritte123/PSPF.
(Chief Bee)
11-17-01 23:22
No 237846
Okay, but there is no such agent that can be added to trap dimethoxybenzene, unfortunately.
(Official Hive Translator)
11-19-01 19:42
No 238411
Well fuck my life I must confess it ain’t as good at all. The yield sucks. Specifically it was 17,7% in SWIM’s case.
SWIM made a rxn w/150 ml water, 70 g of 50% NaMeSO4, 10 g NaOH - to that 9 g HQ in 100 ml water was added in 4 portions over 3 h at reflux (bath temp 140 C, yes that’s how it should bee) – everything under inert atm. 30 min after that time no more oily drops/crystals appeared in the condenser, ~150 ml distillate collected, pure white product filtered out, pressed dry & air-dried, water phase extr’d w/50 ml DCM, dried/evap’d – yielded really negligible amt, ~100 mg of reddish stuff. The weight of the product was 2 g.
SWIM didn’t extract the rxn mixture itself, as he doubts there’s much in it – and it is doomed to bee dirty (the mxtr gets pretty brown at the end)
Well I think it’s not ultimate yet – 1st of all methylsulfate was quite dirty (which SWIM found out only when he got to the rxn – obviously, the Na2CO3 SWIM used to neutralize HMeSO4 contained some washing powder (!!!
I know what you’re thinking of SWIM now – and he deserves it) And, in addition to that – that methylsulfate contained an unknown quantity of Na2CO3, and, what’s worse, possibly, NaHCO3 (neutralizes NaOH) – so, to summarize all said above, it was again not a scientific experiment SWIM thinks he’s going to do that one more time – this time precisely like in the patent (BTW, I noticed they actually used toluene for all extractions! – didn’t specify how they removed it, though)
So there still might bee something similar to a success story yet, although I’m not nearly as optimistic now as I used to bee.
Antoncho
(Master Searcher)
11-20-01 02:30
No 238509
Antoncho, how about using CaCO3 or BaCO3 instead of Na2CO3? CaCO3 is in some OTC antacids, too. CaCO3 is practically insoluble in water. CaSO4 is somewhat soluble and shouldn't interfere with the reaction.
http://www.geocities.com/dritte123/PSPF.
(Master Searcher)
11-22-01 01:49
No 239229
Antoncho, your problem might be with mixing NaOH with the NaMeSO4. Wouldn't that tend to hydrolyze the NaMeSO4? Why not use NaMeSO4 alone in water and add the sodium salt of hydroquinone to it, reflux, steam distill, etc?
Also look at US patent 2490842 and this link (GB patent) http://l2.espacenet.com/dips/bnsviewer?C
I think you're adding things out of order. One method might be as follows:
1. Mix methanol and H2SO4 to get a mixture of MeHSO4, MeOH, H2SO4 and H2O.
2. Pour mixture into water and add excess CaCO3 to neutralyze the H2SO4 and also form Me2Ca(SO4)2.
3. Filter out excess CaCO3 which is insoluble in water.
4. Add a solution of the sodium salt of hydroquinone, heat and stir until reaction is complete.
5. Steam distill the dimethoxybenzene from the reaction mixture.
One problem would be figuring out how much Me2Ca(SO4)2 is in the solution, but you can use an excess of it.
http://www.geocities.com/dritte123/PSPF.