Oh my beloved ones look what I have found. If you don’t immediately say it’s beautiful I’m gonna go hang myself.
IMO, it is so heavenly that I cry every time I think of it - Jesus F. Christ, could it bee so simple!
From Patent GB1557237 (http://l2.espacenet.com/dips/viewer?PN=GB1557237&CY=gb&LG=en&DB=EPD)
:
(https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000267698-file_r0oo.gif) (https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000267698-file_cen2.gif)
May I also humbly note that this is acceptable in case w/EtOH, although unoptimized (yield in the patent’s only ex. is 40%), leading us to exciting 5-Tweetios.
I also bet that, just like vanillin, 2-hydroxy-5-MeO-BA can bee methylated w/NaMeSO4 - but SWIM will have to get to that stage 1st/yet, well this is offtopic anyway.
EDIT:In reality, neither of the too can bee methylated w/NaMeSO4 in a decent yield - SWIM was too naive back then :-[
Antoncho 8)
Antoncho:
i think, if the mechanism the authors suggest is correct (and it does make sense, IMHO), then it'll work for any hydroquinone just fine.
Yes, I needn't be taught the difference. Perhaps I was unclear. This is what I meant. Reduction of the formed alkylated quinone to the hydroquinone, followed by alkylation of the hydroxyl group.
But the alkylated species here is the hydroquinone, not the quinone, so i don't quite get the reasoning...
Yes, that is precisely why it is so beautiful. The benzoquinone acts as sort of a catalyst. I also wonder if more benzoquinone and methanol, with longer reaction times, will result in much higher dimethylated hydroquinone? That would be a wonderful OTC methylation procedure.
maybee interesting 1st to reduce , then alkylate, then alkylate again using NaMeSO4 - i suppose, it doesn't alkylate amines, see what i'm aiming at?
Yes, I see your plan. All of the ideas are interesting to me.
The main point of my joy here - i feel the need to explain - is that p-methoxyphenol, and only p-methoxyphenol, is subject to Reimer-Tiemann formylation, and in good ~70% yield (tested by Karl) - which is very-very OTC, non-toxic - well, it's kitchen chemistry at its best.
Now this reaction I had not yet thought of. Good idea.
I was merely likening this procedure to being also applicable to the quinone alkylation for introducing the ethylamino group for the very novel production of 2C-B. The main issue with that thread, which I understand is not the topic of this discussion, was the final reductive alkylation of the carbonyl groups, whit the issue of protecting the amino group. When I read this, the first thing that I thought of was an easy way to alkylate without protecting the amine. Perhaps you can see my reasoning now.
Good find, Antoncho. I look forward to news of your progress.
PrimoPyro
Vivent Longtemps la Ruche!
Antoncho
Check this out
US 4,469,897
Example #2
5.0 g of hydroquinone, 40 cm.sup.3 of methanol and 1.0 g of cupric chloride are fed into a teflon-lined autoclave having an internal capacity of 100 cm.sup.3. The autoclave is purged with nitrogen and is kept for 2.5 hours at 105.degree. C. On termination of the reaction, an analysis of the mixture indicates the formation of 4.1 g of hydroquinone monomethyl ether (conversion 85%, selectivity 87%).
Or how about this one.
US 4,294,991
Example 20
Hydroquinone (18 g) and benzoquinone (2 g) in methanol (100 ml) with p-toluene sulphonic acid (5 g) were heated under reflux for 6 hours. Samples taken at 3 and 6 hours were analyzed by gas-liquid chromatography and found to have the compositions indicated in Table III.
TABLE III
______________________________________
Hydroquinone
Monomethyl
Sample Benzoquinone
Ether Hydroquinone
______________________________________
After 3 hours
0.12 g 14.6 g 3.6 g
After 6 hours
0.00 g 15.8 g 2.8 g
______________________________________
:)
Stay Informed (http://www.mapinc.org/)
(http://www.mapinc.org/)
This might give you some extraction ideas.
Its another procedure
Production of monoalkyl ethers of dihydric phenols.
US 3274260
Abstract
The title compds. were prepd. by treating an unsubstituted dihydric phenol with an alkylating agent in the presence of an aq. alkali metal hydroxide in a 2-phase system at 65-100°. The alkali metal hydroxide was added gradually in the presence of a relatively large amt. of an immiscible solvent. The monoalkali salt of the dihydric phenol remained in the aq. phase while only a small amt. of the alkali salt of the monoalkyl ether of the dihydric phenol will exist in the mixt. Thus, to 600 g. hydroquinone, 4800 g. C6H6, and 300 g. H2O at reflux temp. (70-5°) was added simultaneously 480 g. 50% aq. NaOH and 756 g. Me2SO4 under anaerobic conditions to minimize oxidn. of the hydroquinone. After refluxing an addnl. hr. the mixt. was acidified to litmus with approx. 12 g. HOAc. The top oil layer was sepd. from the aq. phase, washed with 600 g. 5% aq. Na2SO4 and distd. After removal of the C6H6, a 122-g. head fraction, b20 109-40°, and 525 g. hydroxyanisole (I), b20 141°, were obtained. From the head fraction, a mixt. of hydroquinone di-Me ether (II) and I, was obtained 53 g. I by extn. with aq. NaOH followed by acidification. A total of 578.5 g. I was recovered (78% conversion of hydroquinone). From the non-alkali-sol. portion of the head fraction was obtained 64 g. II (7.7% conversion of hydroquinone). The combined aq layers were extd. with methyl isobutyl ketone. Evapn. of the solvent gave 52 g. of 96% pure hydroquinone. The yields based on converted hydroquinone were 84.5% I and 8.3% II or a yield ratio of monoether to diether of 10:1.
Stay Informed (http://www.mapinc.org/)
(http://www.mapinc.org/)
SWIM is now looking for any suggestions for further purification of the p-MeO-phenol. He's gonna steam-distill it 1st, but to get rid of that toluene... It won't hurt the planned Reimer-Tiemann, but of course having nice crystalline product would bee just... nice
You're going to have to apply a vacuum to the product, a test tube warmed in a water bath and an aspirator would be one good method :)
Osmium - thanks very much for the clarification, now Osmium (or some other xperienced bee), bee so kind - can you give SWIM an advice on rextaliz'n. He has a very general idea on how it is done and never actually performed one ;D
a) While this crap is still an oil, it can bee just mixed w/an unspecified amt of hexane. Will it crash out as crystals on cooling/scratching or is this improbable? How much hexane should bee used per gram of the stuff?
b) Approximately, what percentage of impurities can the procedure tolerate? I mean, not if the crystals won't bee pure enough, but if they form at all.
Therefore the presence of the 2nd substance allows the mixture to boil at a lower temp. than either of the pure substances.
Yep yep yep. This is called Raoul's law or smth, right? :) i'm shy to show my ignorance, of course, but... well...
Anyway, the bp of the mixtr was definitely higher than 100 C - well SWIM was stupid enough not to measure it.
That's very confusing to SWIM.
Antoncho
P.S. Karl was so kind to inform me that p-MeO-phenol "has a kinda pleasant sweet hospital disinfectant aroma" - that's quite consistent w/the results from steam-dist'n. Thanks Karl!
Antoncho
I think that a nonpolar extraction should isolate the product from a basic solution. If it works out as your ref. states you won't have any dimethylether to worry about.
Read this patent US 3274260 and watch how they isolate the products.
http://patft.uspto.gov/netahtml/srchnum.htm (http://patft.uspto.gov/netahtml/srchnum.htm)
Foxy
"After refluxing an addnl. hr. the mixt. was acidified to litmus with approx. 12 g. HOAc. The top oil layer was sepd. from the aq. phase, washed with 600 g. 5% aq. Na2SO4 and distd. After removal of the C6H6, a 122-g. head fraction, b20 109-40°, and 525 g. hydroxyanisole (I), b20 141°, were obtained. From the head fraction, a mixt. of hydroquinone di-Me ether (II) and I, was obtained 53 g. I by extn. with aq. NaOH followed by acidification. A total of 578.5 g. I was recovered (78% conversion of hydroquinone). From the non-alkali-sol. portion of the head fraction was obtained 64 g. II (7.7% conversion of hydroquinone). The combined aq layers were extd. with methyl isobutyl ketone. Evapn. of the solvent gave 52 g. of 96% pure hydroquinone."
Stay Informed (http://www.mapinc.org/)
(http://www.mapinc.org/)
On my ride home, I was thinking about a variety of synthesis, especially the idea of OTC 2,5-dmb. Let's say for clarity that the following chemicals have the numbers:
1 4-hydroxyphenol
2 4-methoxyphenol
3 2-hydroxy-5-methoxybenzaldehyde
4 2,5-dimethoxybenzaldehyde
5 2,5-dihydroxybenzaldehyde
The route you're currently thinking about is 1 to 2 to 3 to 4, but why not go 1 to 5 to 4?
Of course this isn't a new idea, it's been discussed on Rhodium by applying Patent US4755613 (http://l2.espacenet.com/dips/viewer?PN=US4755613&CY=gb&LG=en&DB=EPD)
to hydroquinone... but hopefully this will serve to generate some new dicussion!
P.S. To PP, sorry... I just revised my post (I often do that after I reread it, heh) to include patent reference... I hope that puts my question into a better context.
There is an excellent procedure starting with hydroquinone or 4-MeO-phenol, using SnCl2 or SnCl4, an amine and paraformaldehyde in toluene solvent.
Patent US4151201 (http://l2.espacenet.com/dips/viewer?PN=US4151201&CY=gb&LG=en&DB=EPD)
Patent US6080895 (http://l2.espacenet.com/dips/viewer?PN=US6080895&CY=gb&LG=en&DB=EPD)
JCS Perkin I, 1980, 1862
Then there's another one using phenols, Mg(OMe)2, paraformaldehyde and toluene. 4-MeO-Phenol to the aldehyde in 92%.
JCS Perkin I, 1994, 1823-31
Acta Chem. Scand., 1999, 53, 263-68
I'm not fat just horizontally disproportionate.
Nasreen, Aayesha; Adapa, Srinivas R.
Aromatic hydroxylation by a new cupric nitrate-H2O2-phosphate buffer system.
Org. Prep. Proced. Int. (2000), 32(4), 373-376.
Get this article and it has said transfomation in 90% yeild.
The reagents listed are H2O2, Cu(NO3)2, Na2HPO4, KH2PO4, Water and MeCN.
Looks interesting to Foxy
Can anyone dig up this reference?
Speak Up(Action Alerts!) (http://www.drcnet.org/)
(http://www.drcnet.org/)
PUB-NO: DE003207937C1
DOCUMENT-IDENTIFIER: DE 3207937 C1
TITLE: Process for the preparation of 4-alkoxyphenols
PUBN-DATE: May 19, 1983
ASSIGNEE-INFORMATION:
APPL-NO: DE03207937
APPL-DATE: March 5, 1982
PRIORITY-DATA: DE03207937A (March 5, 1982)
INT-CL_(IPC): C07C041/09
EUR-CL (EPC): C07C041/09
US-CL-CURRENT: 568/650
ABSTRACT:
A novel process for the preparation of 4-alkoxyphenols by reacting hydroquinone with an alcohol at increased temperatures in the presence of catalytic amounts of benzoquinone and an acid is characterised in that perchloric acid is used as the acid. This process gives 4-alkoxyphenols in high yields. 4-Alkoxyphenols are valuable intermediates, for example for the preparation of 4-alkoxyphenyl
carboxylates, which are used as liquid-crystalline compounds.
Patent DE3207937 (http://l2.espacenet.com/dips/viewer?PN=DE3207937&CY=gb&LG=en&DB=EPD)
********************************
PUB-NO: EP000039484A1
DOCUMENT-IDENTIFIER: EP 39484 A1
TITLE: Process for the production of monoethers of hydroquinone and quinol ketales as intermediates thereof.
PUBN-DATE: November 11, 1981
INVENTOR-INFORMATION:
NAME COUNTRY
KELLER, REINHOLD DR N/A
KONZ, ELMAR DR N/A
ASSIGNEE-INFORMATION:
NAME COUNTRY
HOECHST AG DE
APPL-NO: EP81103259
APPL-DATE: April 30, 1981
PRIORITY-DATA: DE03017393A (May 7, 1980)
INT-CL_(IPC): C07C043/23; C07C043/295 ; C07C041/18 ; C07C043/315
EUR-CL (EPC): C07C043/23; C07C043/305, C07C043/315 , C07C045/51 , C07C049/753
, C07D317/64
US-CL-CURRENT: 568/650,568/652
ABSTRACT:
Monoethers of hydroquinone are prepared by reduction of monoketals of
p-benzoquinone, preferably using complex hydrides of boron or aluminium, with a sulphite or molecular hydrogen in the presence of a nickel catalyst until one mole of H2/mole of p-benzoquinone monoketal is absorbed in an inert solvent to give the corresponding quinol ketals and treatment of these with an acid. The quinol ketals formed as intermediates here are novel compounds.
The monoethers of hydroquinone are precursors, intermediates and final products in various subject areas.
Patent EP39484 (http://l2.espacenet.com/dips/viewer?PN=EP39484&CY=gb&LG=en&DB=EPD)
http://www.geocities.com/dritte123/PSPF.html
The hardest thing to explain is the obvious
Study of the steam distillation of phenolic compounds using ultraviolet spectrometry
Norwitz, George; Nataro, Nicole; Keliher, Peter N.
Anal. Chem., 58(3), 639-41 (1986) (https://www.thevespiary.org/rhodium/Rhodium/pdf/steam.distillation.phenolics.pdf)
(https://www.thevespiary.org/rhodium/Rhodium/pdf/steam.distillation.phenolics.pdf)
Abstract
The steam distn. of 42 phenolic compds. was studied using a semimicro steam-distn. app. and UV spectrometry. In the distn., the following gave >95% recoveries: PhOH, 2-RC6H4OH (R = O2N, MeO, Br, Cl), 2,3- and 2,4-Cl2C6H3OH, 2,4,5- and 2,4,6-Cl3C6H2OH, 2,4-Br2C6H3OH, 2-, 3- and 4-cresol, 4,2-Cl(Me)C6H3OH, 2,4-, 2,5-, 2,6-, 3,4- and 3,5-xylenol, 4-RCMe2C6H4OH (R = Me, Et), thymol and carvacrol. The percent recovery for the other phenolic compds. was as follows: 3-O2NC6H4OH, 3.7%; 4-O2NC6H4OH, 1.8%; 3-MeOC6H4OH, 31.1; 4-MeOC6H4OH, 23.2; 3-BrC6H4OH, 79.6; 4-BrC6H4OH, 67.8; 3-ClC6H4OH, 93.5; 4-ClC6H4OH, 91.6; 3,4-Cl2C6H3OH, 64.1; 2,4-(O2N)2C6H3OH, 21.2; picric acid, 0.0; 2-H2NC6H4OH, 0.1; 3-H2NC6H4OH, 0.2; 4-H2NC6H4OH, 0.1; pyrocatechol, 1.6; resorcinol, 0.4; hydroquinone (I), 0.0; pyrogallol, 0.7; and phloroglucinol, 0.1. Examg. the spectra of the undistd., distd. and residual solns. showed that the aminophenols undergo some decompn., and that I is almost completely destroyed during the distn. The important role that H bonding (intermol. and intramol.) plays in the recovery from steam distn. is examd.