Author Topic: P-MeO-phenol from hydroquinone: part II  (Read 16647 times)

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Antoncho

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P-MeO-phenol from hydroquinone: part II
« on: February 10, 2002, 01:39:00 PM »
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

:



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)

PrimoPyro

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #1 on: February 10, 2002, 01:46:00 PM »
Could it be used for alkylated quinones?

Say for 2-ethylamino-1,4-benzoquinone?  ;)

Then only one half of the methylating agent is needed to methylate the remaining hydroxy.  :)

                                                     PrimoPyro

Vivent Longtemps la Ruche!

Antoncho

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #2 on: February 10, 2002, 02:19:00 PM »
Well not really...

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.

But the alkylated species here is the hydroquinone, not the quinone, so i don't quite get the reasoning... 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?

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.

The alternative (starting w/p-diMeO-benzene, which SWIM has successfully made w/NaMeSO4) is Vilsmeier formylation, which requires smth like POCl3 (unaffordable for SWIM) or SOCl2 (can bee made from SCl2, but in a VERY disgusting, stinky way). We'll just leave phosgene alone ::)

The only previously known method of making p-methoxyphenol  (BTW, also found by moi :)  - that's why i say 'part II') involved methylating HQ w/DMS in a two-phase system, whereas the formed product was continuously taken up in toluene, thus avoiding secondary methylation. Besides being non-OTC/toxic, that route still has ~20% of HQ converted to p-diMeObenzene.

An attempt to pull this rxn w/NaMeSO4 was made, but a major problem was encountered: toluene forms a low-boiling azeotrope w/water, and the temp. is insufficient for the NaMeSO4 methylation to effectively take place (although some product still has been isolated). SWIM was planning to try repeating it w/xylene, but w/out much hope, since bp of the azeotrope would bee lower than 100 C anyway.

Now having this procedure in hand... SWIM guesses it's time for him to start saving money for a bottle of chloroform, heh :)  ;D  :)

Antoncho

PrimoPyro

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #3 on: February 10, 2002, 02:46:00 PM »
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!

poix

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #4 on: February 10, 2002, 04:27:00 PM »
Thanx Antoncho, it's very cool. But I'm sad there is only a few % of dimethylether, and tweetios made that way with 2-ethylamino-1,4-benzoquinone would be a mixture of 2 and 5 isomers. Anyway p-methoxy phenol is a most wanted chemical too. For me it is more interesting that 1,4dimethoxy for manuf of 2,5dmb.


"then alkylate again using NaMeSO4 - i suppose, it doesn't alkylate amines, see what i'm aiming at?"

i hope it doesn't alkylate amines, but I don't think so. Some research to be done.

yellium

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #5 on: February 10, 2002, 05:05:00 PM »
This is cool. Apart from the reduction step, this smells like an almost-OTC way to 2CB.  8)

Antoncho

  • Guest
Re: P-MeO-phenol from hydroquinone: part II
« Reply #6 on: February 10, 2002, 06:07:00 PM »
Yes, yes, my dearest friends... I'm glad you appreciated it. This is precisely SWIM's goal - 2C-OTC.

If i ever do that, i'll ask my title to bee changed for that word :)  :)  :)

Antoncho

moo

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #7 on: February 10, 2002, 08:59:00 PM »
The only previously known method for making p-methoxyphenol? Oh my, this should have been posted a long time ago!

J. Chem. Soc 1926, pg. 393:
Quinol Monomethyl Ether.-The method of Ullmann (Annalen, 1903, 327, 116) for the semi-methylation of quinol was found to give poor yields and the following process was adopted after numerous trials. A solution of quinol (110 g.) in sodium hydroxide (100 g.) and water (700 c.c.), contained in a flask filled with hydrogen, was cooled to 12 degrees and vigorously shaken after the addition of neutral methyl sulphate (120 c.c.) in one portion. After about 5 minutes the mixture was cooled and the dimethyl ether collected (33 g., m.p. 56 degrees). The filtrate and washings were acidified with hydrochloric acid and cooled to about 8 degrees for about 1 hour, thereafter the monomethyl ether was collected, washed with ice water, and dried (45 g., m.p. 52-54 degrees). The aqueous solution was extracted with ether and the residue after evaporation of the solvent yielded to benzene a further 30 g. of less pure quinol monomethyl ether, m.p. 41-46 degrees. For our purposes, it was necessary to ensure the absence of quinol from the product. The material was dissolved in benzene and any quinol which crystallized was separated; the solution was then distilled and a product, m.p. 53-54 degrees, collected at 243-246 degrees. This was redissolved in benzene, and the solution repeatedly shaken with small quantities of cold water. The ether was then again distilled, b.p. 243-244 degrees, m.p. 56 degrees. No coloration was developed in alkaline solution in contact with air. The substance crystallised from light petroleum has m.p. 56 degrees, but when heated to about 200 degrees and quickly cooled, the m.p. is 53 degrees, changing in a week or two to 55 degrees. Crystals, m.p. 56 degrees, also change on keeping and the m.p. becomes 55 degrees. Although these changes are small, the phenomenon is a real one.

Yes, quinol is hydroquinone and neutral methyl sulphate is dimethyl sulphate. Probably there was no need to tell but at least for the sake of TFSE :) . There are also a couple of older refs for basically the same reaction which didn't employ hydrogen atmosphere and were not in English. Helvetica Chimica Acta, 7, 951; Monatsh., 45, 581; and the one mentioned above.

Chromic

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #8 on: February 10, 2002, 10:20:00 PM »
So 4-hydroxyphenol to 4-methoxyphenol to 2-hydroxy-5-methoxybenzaldehyde to 2,5-dimethoxybenzaldehyde to the nitrostyrene to the phenylethylamine throw a 4-bromo group on... beautiful! Nice thinking. Best of luck with this procedure...  :)

yellium

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #9 on: February 10, 2002, 11:50:00 PM »
Moo: you can't beat methanol/sulfuric acid with respect to `OTC-ness'.

moo

  • Guest
Re: P-MeO-phenol from hydroquinone: part II
« Reply #10 on: February 11, 2002, 01:00:00 AM »
That is correct. I was also thinking that maybe some other methylation agents might be employed in the same manner... Ending up with mono- and dimethylated products is no problem as they can be separated easily.

Antoncho

  • Guest
Re: P-MeO-phenol from hydroquinone: part II
« Reply #11 on: February 12, 2002, 03:23:00 PM »
Well, oh my beloved companions, oh my six-legged friends; the gimmick clearly works!

It is not complete, yet, but it clearly works.

Benzoquinone was obtained as in you-know-where/quinones.html. The points worth mentioning are :

1)   The crystals were not yellow, but rather green (and a very urgent care was taken to wash the product from impurities w/ice-water)
2)   The still-wet (it was figured, naturally, that the rxn was insensitive to water) 1,7 g quinone was used instead of 1 g dry quinone.

Thence were combined :

a)   50-60 ml MeOH
b)   10 ml H2SO4

The mixtr was brought to RT and in were tossed:

c)   10 g HQ,
d)   1,7 g wet BQ

Hydroquinone forms a cake. It took some shaking to get it all dissolved.

The mixtr is initially black and intransparent (quinhydrone formed), in a half-an-hour it is deeply brownish-red and clear. It was allowed to stand for 18 hrs at temp slightly elevated from normal.

Then the mixtr was alkalified and some preciptt formed, it was extrxt’d w/ toluene – no change in color or whatsoever, SWIM thinks next time he’ll just xtract it after diluting w/aqua.

Then again acidified, ex’d w/toluene, some NaHCO3 stirrred in, decanted, evap’d (SWIM did it on a electric oven/all that stuff, he has no idea how much p-MeO-phenol has evap’d w/toluene. There was some, even more than some  ::) ).

p-MeO-phenol is at this point a disgusting black oil, it doesn’t crystallize other that on good cooling. Fuck. No weight s presently available.

The next run is immediately being put into action, the improved results are soon to bee seen.

The main question – w/what does one recrystallize p-MeO-phenol?  Hexane? SWIM has some.

Hope someone helps.

Antoncho



otto

  • Guest
Re: P-MeO-phenol from hydroquinone: part II
« Reply #12 on: February 12, 2002, 10:18:00 PM »
hi antoncho,

congratulations, this is good news. a very simple method for a good precursor. concerning clean-up, you could steam-distill the product, that should remove most impurities. at least the color will go.

otto

Antoncho

  • Guest
Re: P-MeO-phenol from hydroquinone: part II
« Reply #13 on: February 13, 2002, 01:06:00 AM »
Aww!

Are you positive that it can bee steam-distilled? It's soluble in water like ~4 g/100 ml. But if you say it can, i'll gladly believe you.

And - does anyone by chance know if adding salt will help the steam-distillation - by lessening the solubility? Generally?

Eagerly awaiting your input, bees,

Antoncho

foxy2

  • Guest
Re: P-MeO-phenol from hydroquinone: part II
« Reply #14 on: February 13, 2002, 04:43:00 AM »
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
    ______________________________________


:)

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Chromic

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #15 on: February 13, 2002, 04:46:00 AM »
I'm positive that it can be steam distilled. GBL, a water miscible solvent can be steam distilled even though it's completely soluble in water. Don't try to recrystallize until you have crystals.

(snip - I had posted suggestions to clean up the mix, but it's basically the same you're doing - snip)

foxy2

  • Guest
Re: P-MeO-phenol from hydroquinone: part II
« Reply #16 on: February 13, 2002, 04:59:00 AM »
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. 

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Osmium

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #17 on: February 13, 2002, 12:39:00 PM »
Acidifying a solution containing 480 g. 50% aq. NaOH with only 12g HOAc???
Strange.


I'm not fat just horizontally disproportionate.

PrimoPyro

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #18 on: February 13, 2002, 12:47:00 PM »
Perhaps a typo? 512g HOAc maybe?

The Water Will Be Your Only Mirror

Antoncho

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Re: P-MeO-phenol from hydroquinone: part II
« Reply #19 on: February 14, 2002, 05:00:00 PM »
Look what's been happening lately.

SWIM combined in a 250 ml flask 55 ml MeOH, 11 ml 92% H2SO4, 10 g hydroquinone (HQ) and 1 g (rather dry this time) benzoquinone. Just as beefore, the soln turned 1st intransparent and black, then in a half-an-hour all completely clear & dark reddish-brown. All was left for 20 h at RT w/out any stirring or even occasional shaking.

After the passage of the said time, into the mixtr was added 100 ml sat'd NaCl soln. - turned milky-brownish; extracted w/50 + 30 ml toluene, all color completely gone into the organic layer.

The toluene was stirred w/some solid NaHCO3 until all acid neutralized, then distilled off at oil bath temp ~130 C (it wasn't dried - assumed water would bee removed azeotropically, advice here? was SWIM wrong? Guess he was.)

Now - note this - toluene wasn't removed completely. The contents of the flask were poured into a glazed metal plate put on a boling water bath, and placed under draught. It was fucken incubated until almost all smell of toluene was gone, but never got absolutely rid of it! The moral: use smth lower-boiling for the extract'n!! SWIM isn't happy w/his results using toluene, at all. Possibly could result in lower selectivity, but considering the product has to bee further purified anyway (it's dark brown in color), it proally doesn't matter.

The brown oil was cooled, scratched somewhat - all immediately crystallized, the crystals were much nicer that in the previous attempt (when they looked more like dirt), although still somewhat moist/damp - guess some residual toluene or water.

The weight of this crude product was 8,4 g.

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 :) .

2 PrimoPyro: sorry, but i ran out of Internet - all can do now is to post this messg ;)  Later.

Antoncho

P.S. Ya lyublyu Yul'ku!!! Everyone happy holiday!!!