05-19-01 23:55
No 195690
Preparation of Ethyl Nitrite
Mix 288g of 95% ethanol (190 Proof/Everclear) with 290mL of dH2O and 300g 98% H2SO4 and chill in the freezer. In a 2L RBF with a magnetic stirbar, dissolve 227.7g sodium nitrite in 725mL dH2O and cool in the freezer for a few hours, without freezing the solution (some precipitation will occur). Place the RBF in a -10C ice bath. Add the ethanol/water solution to an addition funnel positioned above the RBF. Add the ethanol solution dropwise to the nitrite solution over a period of 1-2h {with gentle stirring}, and monitor the temperature of the solution, assuring that it does not rise above 6-9C. Once the addition is complete, allow the solution to cool in the bath, and filter out the precipitated sodium sulfate in a chilled buchner funnel/filtering flask (use very low vacuum, or the ethyl nitrite will boil away), and wash the filter cace with a little ice-cold 95% ethanol. Remove the flask and pour the contents into a 2L separatory funnel which has been chilled in the freezer, remove the aqueous layer, and wash the nitrite with 500 mL of a 5% sodium bicarbonate solution which has been chilled in the freezer. Drain the nitrite into a 2L RBF and add anhydrous, denatured ethanol to bring the final volume to 1L. Dry over 100g sodium sulfate for 15 minutes, filter, and rinse the cake with ~100mL ethanol. {You must dilute before filtering or the ethyl nitrite will froth violently and you will get loopy
}Nitrite Wacker
Take the ethyl nitrite solution from above, bring the total volume to 2L with anhydrous ethanol {Used denatured anhydrous, 5% MeOH, or make your own from 95% and CaO}, and place in a 4L filter flask, stoppered, with a tube leading from the outlet into a jug of 2% HCl. Add 2.65g PdCl2 (0.015 moles) and 10.08g CuCl2 (0.075 moles, anhydrous) to the flask and gently warm the flask to ~30C. Add 325g of fractionally distilled safrole (2 moles) to the flask, and continue stirring for 8h at 30C. Once complete, add 500mL H2O to the flask and raise the temperature to 50C, holding it there for 40 minutes. When this is done, filter the contents over celite, rinse with 100mL EtOH, and optionally roto-vap off ~1200 mL of the EtOH. Flood the contents with 1200mL of 5% HCl and extract the precipitated ketone 3x with 400 mL of DCM. Wash the pooled extracts with water, saturated sodium bicarbonate solution, and brine. Filter the organic phase through celite to remove some residual, precipitated metals. Dry the extract over sodium sulfate, filter, and rinse the cake with DCM. Rotary evaporate the solvent at atmospheric pressure at the steam bath, then fractionally distill the piperonylacetone over a 300mm column packed with glass beads at 10.0 mmHg (149-152C). Optionally, run a chaser to clear the column, or extract and distill with a smaller rig/shorter path. Store the pure ketone in an equal volume of anhydrous methanol, under nitrogen, in the freezer. Weight of piperonylacetone; 321.5g, 83.5%.
Don't forget to use a water-trap to prevent suck-back should it occur!!!
I believe there may have been additional piperonylacetone which wasn't collected, or it might have been mostly contaminant. This was by no means a first shot at the nitrite. An aspiring young neophyte, a KrZ apprentice, allowed a retiree to conduct some small tinkerings with it on his premises, and this is the scale-up of the most fruitful of these meanderings. Methyl nitrites produced unsatisfactory results, and were quite malodorous during the gassing. Perhaps this was due to escaping MeONO, and yes, that was with a diffusion tube into cold MeOH. I don't care what any of you say, bubbling gases into solutions, no matter how cold, is no way to go about things. n-Butyl nitrites proceeded according to the patent {w/o cocatalyst} but that damn nBuOH stinks to hell and annoys me in general. Isopropyl nitrites were too hindered to form the dialkoxides effectively {my theory, yields sucked regardless}. Ethyl nitrite was settled on, and while aq. solutions worked effectively with no cocatalyst {as with MeONO & nBuONO}, the turnover thing just wasn't happening. We upped the nitrite concentration to no alleive, then went with anhydrous conditions, and acheived suitable results. There was still a lag time of 1-2h with the above conditions.
After this there has been some tinkering with the sulfided Pt catalyst, including atmospheric hydrogenations and ground-up catalyst preparation. Hopefully that will be detailed soon, although there are still a few optimizations to investigate.
(Hive Addict)
05-20-01 00:40
No 195694
KRZ you are truely a hallucinogenius.
Bravo
Do Your Part To Win The War
(Hive Bee)
05-21-01 13:40
No 195918
Time ago I tried it, but when making the ethyl nitrite I got a big precipitate of sodium sulfate. I tried to dissolve it adding cold water, but finally temp went up to the bp of ethyl nitrite, and I was a bit stoned with some kind of popper effects. It is really important to work always below 5 C or less.
It is a very nice work having it is easy for kitchen chemists and cocatalysts works...
Thank you again KrZ.
(Hive Bee)
05-22-01 10:09
No 196082
Oops, KrZ, I've been re-reading your procedure, and I guess you forgot to say that sulfuric acid was added and chilled with the ethanol and water right ?
I think the NaNO2 won't react with plain ethanol and water, as it doesn't with methanol and water. Am I right ?
Then it would be nice to correct your post in order to not confuse the bees.
(Hallucinogenius)
05-22-01 22:48
No 196206
Damnit, I fucking forgot to put that in. I can't change it now because of that stupid 12 hour bullshit. GODDAMNIT. grrr... 
(Chief Bee)
05-23-01 01:14
No 196257
Krz: Tell us how much sulfuric acid you added, and how you did it, and I'll edit the post for you, as well as archiving it on my site.
http://rhodium.lycaeum.org
(Hallucinogenius)
05-23-01 09:59
No 196359
300g 98% H2SO4. The Na2SO4 does precipitate (As sunlight said), but it was filtered out at the end.
(Chief Bee)
05-23-01 12:58
No 196410
So, I have changed your post. Is everything satisfactory, so that I can put it on my page now?
http://rhodium.lycaeum.org
(Hive Bee)
05-23-01 12:59
No 196411
Mmmm, the procedure is very promising, but work up could complicate due the low bp of ethyl nitrite (it's 17 C or so no ?) Filtering, drying... Room temp here is about 25 C. I guess it can be done with extreme care, freezing all the glasware and solutions and water to filteer etc... previously.
Any idea about why the cocatalyst doesn't work with MeONO while there are explicit examples (both anhydrous and hydrous) in the patent ?
How can we drye MeONO and remove possible NO gasses, bubbling it in a NaOH solution then passing it through NaOH pellets? Or it will decompose the nitrite ?
(Chief Bee)
05-23-01 13:04
No 196413
I'm afraid NaOH would react with MeONO forming methanol and various nitrous salts.
http://rhodium.lycaeum.org
(Hive Bee)
05-23-01 13:28
No 196414
Shit, and sulfuric acid instead of NaOH ? Other option is silica gel...
And what about using DCM as solvent, the patent talks about toluene, ethyl acetate etc... but not halogenated solvents, may be it is due they will react with the nitrite ?
Thanks for your answer.
(Hive Bee)
05-23-01 14:16
No 196421
Rhodium, don't forget to include the filtering of the sodium sulfate salts before go to the sep. funel with pre chilled glassware and washing the filter with cold water or freezed solvent (better option). I guess it is necessary to use very low vacuum.
So how did you make it KrZ ?
It is very surprising when you find the precipitate, and you have not too much time to react, the ethyl nitrite scapes very soon.
(Newbee)
01-05-02 06:26
No 252853
I recently tried this method on 22.5 mL of safrole. Instead of isolating the EtONO, I produced it at room temperature, and passed the evolved gas through an ice cold condeser, letting the condensate drip into a flask of cold EtOH. I used this solution to carry out the reaction in. When I distilled the product, though, I only obtained 5.5 mL of a yellow colored ketone (bright, transparent yellow, not dirty looking. kind of like medium colored piss) that came over at 165 - 172C under ~40 mm Hg (safrole came over at 135 - 140C). The rest of the distillate came over before the ketone, a good deal of it around the bp of safrole. My total yield of ketone in the combined distillate was probably ~8 mL. I ran the reaction for 8 hours, keeping the temperature between 30 and 35C for most of the reaction. The only significant variation from your procdure other than the prep of the EtONO was that I used anhydrous CuCl2. Could this be the reason for my low yield? Any help would be appreciated.
(Pioneer Researcher)
01-07-02 02:35
No 253373
There's a typo in the recipe, I told it to KrZ and I thought he corrected it.
227 gr. of NaNO2 are 3.28 mol, not enough to react with 2 mol of safrol that needs 4 at least. 5 mols, better 6 would be desirable, which is the quantity that corresponds with 300 gr of H2SO4 (422 gr NaNO2).
The desirable amount is at least 2.5 mols of nitrite per mol of oleofin, 3.28 per 2 mols can explain the low yields.
In other hand, if you just bubbled the EtONO to the ethanol, it would contain some water, it should be dried with silica gel or other agent suitable for it.
Your variation of the collection of ethyl nitrite is good, and may make this procedure more workable. But please check your ketone and inform us (40 mm is too much for 165 C, it should be 15 mm).
(Newbee)
01-07-02 07:33
No 253451
According to Perry's Chemical Engineering Handbook, safrole boils at 137C at 40 mm. Since ketone boils 25-30C higher than safrole, 167C would be a reasonable bp for the ketone at 40 mm. Do you have data for the bp of ketone that indicates otherwise? If so, could you please post it or send it to me? I didn't bubble the EtONO into EtOH. I passed the gasseous EtONO through an ice cold condenser and let it drip into the EtOH. I probably still should dry it, though. Would MgSO4 work? Also, would it be better to use the dihydrate or the anhydrous form of CuCl2?
(Pioneer Researcher)
01-07-02 15:02
No 253564
Yes, you distilled it, sorry, I understood the idea but my mind was in other part when I wrote the post. It a good procedure. It is a good solution, unsmelling, nitrites are toxic. For anhydrous conditions like in KrZ post, you should dry it (ethanol+EtONO) with MgSO4, and use (like him, re-read his post) CuCl2 anhydrous. The reaction should work even with some water, but...
This is from an old post from Osmium:
From Beilstein:
80 (0.08 torr)
103-104 (0.2 torr)
110-111 (0.8 torr)
132-133 (3 torr)
140-145 (9 torr)
149-151 (10 torr)
151 (10 torr)
163 (16 torr)
168 (17 torr)
283-84 (760 torr)
283-85 (760 torr)
Density:
1.2017 (17.5°C) in g/cm^3
1.203 (20)
1.2035 (22)
1.204 (25)
1.205 (20)
1.2197 (0)
Refractive Index:
1.54 (589nm, 26°C)
1.5428 (589, 20)
1.543 (589, 20)
1.5445 (589, 25)
1.545 (589, 15)
1.542 (589, 20)
These numbers differ because they were reported by different scientists.
Beilstein Registry No: 164033
CAS Registry No: 4676-39-5
Molecular Formula: C10H10O3
Molecular weight: 178.19
(Newbee)
01-12-02 09:55
No 255567
I ran the reaction another time on the same scale, but used the proper amount of EtONO this time. It still fucked up. The reaction seemed to run fine, running b/t 30-35C and steadily evolving NO gas. Workup also went good, but when I distilled it, it really did some fucked up shit. The first fraction came over between 111-116C and I have no fucking clue what it is. It was a clear, refractive liquid that smelled somewhat like EtONO dissolved in EtOH. I collected about 12 g of this stuff. No safrole came over, and about 7-8 g of ketone came over. This was from a 23 g safrole reaction. Under the same vacuum, safrole comes over at around 130C, so the pressure is around 30 mm. The ketone came over between 154C-164C and was neon yellow/green in color. I would estimate that this mystery fraction has a bp of 210-220C at atmospheric pressure. Does anyone have any idea what this fraction might be? I have two theories:
1) It is some sort of azeotrope formed b/t the ketone and another mystery compound. This other compound may be the ethyl acetal of the ketone that did not completely hydrolyze, even though I performed the hydrolysis exactly as the procedure described.
2) The mystery liquid is a degradation product of the ketone or the safrole. Since it has a lower bp, it is not a polymer. In order for it to have a lower bp than safrole, it would have to have a lesser molecular mass, since safrole contains no polar bonding other than the MD ring, which if hydrolyzed would only increase the bp.
I would put my money on the first theory. Does anyone else have any ideas?
Also, I could have sworn that I got a good deal of safrole to come over with my first attempt at the reaction. I redistilled the prerun/postrun for that distillation and did not get back any significant amount of safrole. I only got the mystery liquid and ketone back. I had let it sit in my freezer for about a week, diluted with acetone.
One more thing. The EtOH I am using to run the reaction in is Parks brand denatured alcohol, and the acetone I used to dilute the above mentioned mixture was also Parks brand.
(Stranger)
01-12-02 22:35
No 255694
I admire KrZ greatly, but "piperonylacetone" is not MDP2P, as it has one too many carbons. Piperonyl methyl ketone is the right word if you want to use the term piperonyl. Shulgin apparently ordered true piperonylacetone one time and made some kind of funky 4C compound by mistake.
(Pioneer Researcher)
01-14-02 00:32
No 256048
May be it was not well hydrolized and you got some of the diethoxy MD phenyl propane ? Don't know. There's something that worries me, denatured alcohol is, acording with Meck, ethanol 95 % (azeotrope) + denaturants such as methanol or others. You should check the exact composition of your denatured alcohol, may be it has something that interferes in the rxn. If you can get (or make) absolute ethnaol it would be better, I'm convinced that the ethyl nitrite will work as well with methanol, or even IPA, teh only problem is that can be a interchange of nitrite groups, producing some methyl nitrite (waht could be even desirable) or isopropyl nitrite.
Be patient, your idea of distill the ethyl nitrite is good, I think you can get something god for all us.
(Newbee)
01-16-02 03:11
No 256932
I think that I was right about the incomplete hydrolysis. I went ahead and re-hydrolyzed the mystery liquid (which was clear to begin with) and got back a yellowish liquid that smelled of both safrole and ketone. The original liquid did not have a ketone smell to it, and instead had a smell similar to that of EtONO. When rethinking the wacker reaction that I performed, I realized what might be the problem. While I had let it react for 8 hours, some suck-back had occured and water had gotten into the reaction mixture. I assumed that this would not be a problem, since water would be added anyway, and suckback probably occured towards the completion of the rxn when the evolution of NO ceased. This additional water, however, caused a phase separation during the hydrolysis, so the acetal, and the water were in two separate layers and very little hydrolysis occured. I'll try distilling the mixture from the 2nd hydrolysis tonight and see what I get.
(Hallucinogenius)
01-16-02 18:30
No 257244
piperonyl acetone [3160-37-0]
Synonyms: heliotropyl acetone; 3,4-methylenedioxybenzyl acetone; 4-(3,4-methylenedioxyphenyl)-2-butanone;
3,4-Methylenedioxybenzylideneacetone;
C11H12O3
192.214
NYAH!
(Hallucinogenius)
01-16-02 23:27
No 257308
Guess that means I never did anything illegal!! HOORAY!!! I never noticed that... hrmm... Piperonyl should be like phenyl... stupid nomenclature...
(Distinctive Doe)
01-16-02 23:28
No 257310
Nice to see you around KrZ
I hate my government, does this mean I'm a terrorist??