Author Topic: Some results  (Read 7825 times)

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Chromic

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Some results
« on: December 12, 2003, 04:01:00 AM »
No one's going to bite? Damn you! Ok, some preliminary results...

48.6g (.3mol) isosafrole peracetic (isosaffy is known to be 99%+, peracetic aged 95 hours before use at room temp), reaction seemed to go as usual (i.e. exothermic at 5 minutes, and tapered after 20 mins). 60.5g glycol isolated. Rearranged 2.5 hours with 5M hydrochloric (15%) instead of 15% H2SO4, using methanol. 49.1g crude ketone recovered. Distilled 41.8g of light orange-red ketone at 275-295C (most coming over around 285C, this is strange, usually see a light yellow ketone). (btw, does anyone note that this is a 78% yield?! normally the highest yield I've seen before this was 64% yield when using 15% h2so4--and keep in mind, I did not vacuum distill which would up the yield further--and that 64% I saw was using anethole not isosafrole) There was no forerun and little remained in the flask after.

Went to test with some old saturated bisulfite sol'n hanging around (still stunk like SO2 so I figure it's okay), but it came up negative (not even chicken fat formed...)

Uhoh. What is this oil? Doesn't smell like isosafrole. Smells like what I remember ketone to be. What could it be?

What should I recommend to this person to do? ... distill again? throw it out? aminate anyways?

Chromic

  • Guest
Fractionally distilled
« Reply #1 on: December 12, 2003, 04:53:00 AM »
The oil was then fractionally distilled... kept what came across at 280-290C, most came across at 286C (80% of the oil was recovered). (about 10% was <280C, other 10% turned to crap in the flask) This is light yellow, smells like ketone, flows like ketone... I just don't get it!?! Perhaps his bisulfite has gone bad...

Vitus_Verdegast

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that could very well be
« Reply #2 on: December 12, 2003, 07:02:00 AM »
Went to test with some old saturated bisulfite sol'n hanging around

Bisulfite solutions are not something you want to keep for long, as the bisulfite will oxidize to bisulfate. SWIM had this problem once too, he tried to form the addition compound with a substituted benzaldehyde using an old aqueous solution of NaHSO3 (also smelled/stank like SO2 does) but failed, so he figured the bisulfite must have been oxidized. Then freshly made NaHSO3 solution was tried, which worked without problems.


Chromic

  • Guest
HCl is so good it's GOLDEN!
« Reply #3 on: December 12, 2003, 08:38:00 AM »
V_V, you're right on the money. Thank you! *hugs*

This ketone of a friend's is good, infact, great! It turned to slush in about 1-2 minutes in the freshly made bisulfite solution (normally this can take 5-60 minutes)

May I make a suggestion to any other bee to try using a 15% HCl rearrangement? Write-up is as follows (attentive bees will notice this is actually 5M HCl):

From the extracts from a peracid rxn containing .3mol isosaffy (48.6g), the glycol is added to: 75mL MeOH, 125ml H2O then 125ml 31.25% HCl. The mixture is refluxed 2.5 hours, the oil drained from the bottom of a sep funnel and further extracted 3x60ml DCM. The ketone distilled and at least an 80% yield can be had...

I'm expecting this yield to be closer to 85% if this guy had a better lab. This really is phenomenal if it's as good as it appears to me. I always heard of 60% yields with the peracetic/performic (likely because of the losses in the acid-catalyzed rearrangement), and I knew it's possible to hit 70% with a proper vacuum distillation... so I wouldn't be surprised if one can hit 85% of theory using this HCl rearrangement. It's almost as great as Ritter's work on the tosic method, and certainly a lot more OTC.

Chromic

  • Guest
Repeated once more
« Reply #4 on: December 12, 2003, 08:41:00 AM »
This is a 14% higher yield than I've ever seen before... plus uses an easier to find, handle, and prepare acid.

Rhodium

  • Guest
Effect of various acids on pinacol rearrangement
« Reply #5 on: December 12, 2003, 09:03:00 AM »
Effect of various acids at different concentrations on the pinacol rearrangement
Monica De Lezaeta, Wajiha Sattara, Paris Svoronos, Sasan Karimi, Gopal Subramaniam

Tetrahedron Letters 43(51), 9307-9309 (2002)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/pinacol.various.acids.pdf)
DOI:

10.1016/S0040-4039(02)02379-1



Abstract
The formation of side products in the pinacol–pinacolone rearrangement was studied as a function of concentration and strength of various aqueous acids using 1H NMR spectroscopy. In all cases, pinacolone was the principal product and in most cases, its relative yield decreased with respect to 2,3-dimethyl-1,3-butadiene, when the acid concentration was lowered or the corresponding conjugate base was added.


Chromic

  • Guest
Good good
« Reply #6 on: December 12, 2003, 07:18:00 PM »
Forms the ketoxime just fine. In fact the ketoxime is white, I thought he had fucked up and it was the inorganic salt that always forms... before it's always been off-white. This is some nice ketone. I highly recommend this method to any other bee who may be reading this.

P.S. please, someone, confirm this! if this is as easy as it seems, it should go into the peracid faq ASAP.

Antibody2

  • Guest
thats really cool chromic!
« Reply #7 on: December 13, 2003, 06:39:00 AM »
thats really cool chromic!


Chromic

  • Guest
Yield using the ketone
« Reply #8 on: December 13, 2003, 08:18:00 AM »
There was 17.9g of amine hydrochloride from 15.1g of ketone (this yield is before recrystallizing--btw this is 92% of theory from a Al/Hg). The yields on the ketoxime were likewise really good as well.

Somebody--anybody test this... I haven't heard of a smoother rearrangement in my life. (with exception of the tosic acid method that Ritter, Scoobie Doo and others mentioned) People using H2SO4 may just be throwing away 15% of their potential ketone (plus getting more crap from undesired side-reactions).

P.S. the yield on 50mmol of ketone was 92%. (8.8g ketoxime from 8.9g ketone)

Chromic

  • Guest
Asarone
« Reply #9 on: December 13, 2003, 08:31:00 AM »
I wonder if this may be a decent way to TMA-2. An H2SO4 rearrangement will really chew up the asarone oxidation product (glycol, monoacetyl glycol, epoxide, whatever it is)--although it most definitely works. I wonder if this rearrangement would be more gentle and give a better yield of asarone's ketone.

Antibody2

  • Guest
that would depend chromic, if the asarone...
« Reply #10 on: December 16, 2003, 03:50:00 AM »
that would depend chromic, if the asarone survived the peracetic rxn. My impression was that asarone decomposed/polymerized in the oxidation step not the hydrolysis step.

This assumption is based on some old pseudonitration experiments i did with asarone using HOAc as the solvent. The asarone became a purple ball of tar when left nitrating in HOAc overnight. I don't know for certain that it was the GAA alone that caused this or whether the NO2 played a role as well.

As well, goiterjoe did some peracetic trials on asarone with no sucess as far as i know, but again i am not sure if it was the oxidation or the hydrolysis that failed. Ask him.


Chromic

  • Guest
tma-2
« Reply #11 on: December 16, 2003, 09:50:00 AM »
I made tma-2 with the peracetic in DCM--the problem was not the oxidation.

The problem was the H2SO4 hydrolysis. The asarone epoxide that came out of the peracetic was beautiful. The ketone was however crap, no better than 25-50% pure if I had to guess. It still made good tma-2 through your oxime reduction... I tripped my balls off and thought I was going to die.

That's why I'm wondering about the HCl hydrolysis. Does no one make ketones anymore? Come on guys! This could be a revolution for anyone using peracid techniques. (oxone, peracetic, performic)

edit: the hurry is that a lot of bees might be wasting a good part of their yields (and precious isosafrole). If this works, I'd like to see the word get out asap on rhodium's site. okay, sure, I'm impatient...  :)  btw it's good to hear that someone else will test this out as well.

hypo

  • Guest
hey now...
« Reply #12 on: December 16, 2003, 09:53:00 AM »
what's the hurry? i'll try this on iso-myristicin, but please
give me a few weeks.  ;)


otto

  • Guest
hi Chromic, otto has had the same experiences.
« Reply #13 on: December 16, 2003, 10:22:00 PM »
hi Chromic,

otto has had the same experiences. the asarone epoxide has been made nicely using bleach but then h2so4 hydrolysis gave only 30% yield of the ketone after purification (chromatography).

otto

hellman

  • Guest
kudos
« Reply #14 on: February 20, 2004, 11:27:00 AM »
This is an incredible achievement,

Is this an otc dream, this with the peracetic, performic(oxalic+glcerin), many bees fear is further reduced,

Excellent chromic, this should be written up everywhere,
This is especially handy to oz bees, that have no access to h2so4, this is a great way!!!

Well done

hm


amine

  • Guest
Chromic is god!!!
« Reply #15 on: April 14, 2004, 08:56:00 AM »
Wow, as we speak, swim has the most beautiful ketone distilling a light green color comming over at around 147C.  Swim used chromics technique and wow, it is sooooo much easier than the H2SO4 hydrolysis, the reaction looks clean throughout and you can see product formation, the syruppy glycol slowly turns into globules of a dark golden color. The rest of the solution remains orange.
Post reaction a beautiful dark golden oil falls to the bottom.

Wow....this by far is the cleanest method swim has used.
Props to chromic.

had swims vacuum adapter break :( but swim ghetto rigged something that works (using a 2 neck 500ml flask...) and a stopper with a hole in it.

ApprenticeCook

  • Guest
Re: Hellman - This is especially handy to oz...
« Reply #16 on: April 14, 2004, 12:22:00 PM »

Hellman - This is especially handy to oz bees, that have no access to h2so4, this is a great way!!!


Jesus could you be any more WRONG! oz bee, speaking from ACTUALLY BEING ONE access to sulphuric acid is a peice of piss.... waltz your ass to ANY (no sources from me) and say "hey can i have some car battery acid 98%?" and all they say is "OK that will be $4 a litre" fuck sake....  >:(  the bottle has written on it in big fat ass letters H2SO4 98% along with all the normal crap danger blah blah blah....

NO ACCESS my ass.... cant name a source but if you think hard enough you'll figure it out... hellman may not though..


Vitus_Verdegast

  • Guest
never mind hellman
« Reply #17 on: April 14, 2004, 01:20:00 PM »
He doesn't seem to know that the degree of industrialization of a country is measured in the tonnes of sulfuric acid it consumes every year.  ;D


Vitus_Verdegast

  • Guest
Preparation of 2,3-DM-4,5-MDP2P
« Reply #18 on: April 16, 2004, 01:00:00 AM »
Preparation of 2,3-dimethoxy-4,5-methylenedioxyphenylacetone by buffered performic acid oxidation of isodillapiole, followed by Pinacol rearrangement of the intermediate glycol (formyl ester) using aqueous hydrochloric acid.
by Vitus Verdegast

In a 1L three-neck flask, set up with an addition funnel, was added 29.5 g (0.142 mol) isodillapiole dissolved in 55 ml dichloromethane, followed by 7.1 g (0.08 mol) sodium bicarbonate. To the addition funnel was added a solution of performic acid, which was prepared an hour before by mixing 30.6 g (0.225 mol) 25% hydrogen peroxide and 29 ml (35 g, 0.645 mol) 85% formic acid. This was added dropwise to the stirring suspension in the flask, which caused a lot of foaming due to the liberation of CO2. The addition took around 90 minutes, and the two-phase mixture was allowed to stir for an additional 16 hours. At the 3 hour point, a TLC was done on a sample (solvent: methanol, detection: iodine vapours) which showed a large spot -presumably of both the glycol and glycol formyl ester- and only a very minor spot of isodillapiole, so it is safe to say that most of the olefin was consumed at this point.

The organic layer was separated and washed twice with water. The dichloromethane was distilled off and the resulting dark-red oil was taken up in 40 ml methanol. To this was added 60 ml water, followed by 60 ml 29.5% hydrochloric acid. This mixture was refluxed for 3 hours and after letting it cool to room temperature, the dark oily precipitate was separated, and the mother liquor extracted once with 60 ml dichloromethane. The extract and the oil were pooled, washed twice with water and once with an aqueous NaHCO3 solution. The washings and the mother liquor were pooled and a small amount of oil was separated off and added to the organic solution1. The dichloromethane was distilled off, then vacuum was applied and 17 g of greenish-yellow 2,3-dimethoxy-4,5-methylenedioxyphenylacetone came over at 195°C at the fridge pump (50% overall yield)2.


1. TLC (solvent: petroleum ether, detection: iodine vapours) showed that all glycol (formyl ester) was consumed and the post-reaction extract gave a single spot of the ketone, at a somewhat lower Rf value than the former. It must be noted that both the glycol (formyl ester) and the ketone contained an impurity which did not elute with this solvent system.

2. The somewhat low yield was due to the use of an insufficient vacuum, as during the whole distillation smoke was seen entering the receiver. The column was warmed with an electric insulating mantle to prevent massive polymerisation caused by heating the oil too long. To obtain better results, the boiling point of the ketone must be kept under at least 185°C, as was observed before by Antibody2 3. A dark, viscous, sharp-smelling residue was left in the distilling flask, which solidified on cooling. The colour of the ketone went from greenish-yellow to a more golden tint after standing an hour at room temperature.

3.

Post 250280

(Antibody2: "Complete synthesis of DMMDA-2 and DMMDMA-2", Methods Discourse)



Vitus_Verdegast

  • Guest
Well, Chromic,
« Reply #19 on: April 16, 2004, 01:41:00 AM »
Here is what you asked for, although the final part is probably not what you wanted  ;) .
I should have known that my good friend the fridge pump would not be able to do the job properly, but at least it is proven that it is possible to obtain a workable amount of 2,3-dimethoxy-4,5-methylenedioxyphenylacetone using a fridge pump (or an aspirator for that matter).

I'm thinking of trying your procedure again with a lower boiling ketone, like 4-methoxyphenylacetone, to get a more accurate view on the differences between using HCl and H2SO4.

While we are at it, by the way, does anyone know of some good parfumery formulas? I was thinking of utilizing these good scenting compounds (especially the latter 4-methoxy compound) in deodorant or candles maybe.