posted 01-01-2000 02:36 PM         

I wrote this up many months ago as a personal guide for my friend Mr. Agidk to follow, but then I modified it to reflect the use of MeOH instead of DMF as the solvent, and realized that other bees might enjoy reading it.

Big thanks go to Getafix, whose original writeup this was adapted from. His succinct writing style and willingness to help were a gift to the blossoming bee.

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Materials:
400mL MeOH (methanol)
50mL distilled H2O
150g p-Benzoquinone
2g palladium (II) chloride
178g safrole
DCM (methylene chloride; dichloromethane)
NaCl (non-iodized table salt)
Sodium bicarbonate (baking soda)
5% NaOH (sodium hydroxide)
HCl (hydrochloric acid, from muriatic acid)
Magnesium sulfate drying agent (epsom salts baked in 400°F oven for 2 hours)

Method:
1. In a 2L flask place 400ml MeOH, 50ml dH2O, 150g p-Benzoquinone and 2g PdCl2 and leave to stir for a minimum of 60 minutes.
2. Place 178g safrole mixed with a bit of MeOH in an addition funnel.
3. Add safrole dropwise from the addition funnel over 60 minutes or more.
4. After the safrole addition is complete, leave mixture stirring for 8 hours. (If you must stop at this point and resume another day, be sure to put the mixture in the freezer, sealed well. The raw ketone decomposes unless stored at freezer temperatures.)
5. Filter out the solids present in the mixture, which are hydroquinone (the degradation product of the benzoquinone) and PdCl2. This can be done by vacuum filtration or by simple gravity filtration with coffee filters. Some prefer gravity filtration with this synthesis because the solids produced in this reaction are very fine and are problematic to filter with vacuum. I don't recommend trying to recycle the PdCl2, as it is too difficult to separate from the hydroquinone to be worthwhile.
6. Flood mixture with 1.7L 3N (~10%) HCl. (Here's the quick math: add 500mL of 31% HCl [muriatic acid] to 1150mL H2O to get 1.65L ~10% HCl—close enough for this purpose.)
7. Extract flooded mixture with 3 portions of DCM (1 x 500mL, 1 x 250mL, 1 x 100mL) in a large separatory funnel. The desired raw product, MDP-2-P (“ketone”), migrates into the DCM as an oil. Separate the DCM/ketone layers and combine them.
(Note: when you first hit it with the DCM you will probably observe a bit of scum which will float on top of the water layer, which will work its way down during these three extractions to appear as a blob of spongy semi-solid interface. It’s actually very mobile and easy to work around; simply avoid allowing it into your DCM separations. The same thing will happen in your washes in steps 10, 11 and 12 below, but by then you will be quite the pro at working with it.)
8. Extract water layer with a final small amount of DCM.
9. Add this final small DCM extraction to the combined oil/DCM solution from step 8.
10. Wash the ketone/DCM solution with saturated sodium bicarbonate in water twice (500mL each wash).
11. Wash the ketone/DCM solution with saturated NaCl 3 times (400-500mL each wash).
(Note: as you do these bicarb and salt water washes, you should be seeing the ketone/DCM solution getting progressively more greenish colored; this is visible in the film of solution that runs down the inner surface of the sep funnel).
12. Wash the ketone/DCM solution 3 times with 500mL 5% NaOH (500mL each wash). If you did step 5, you will have a very easy separation.
(Note: you should also see a very noticeable color change upon doing the first of these three washes wherein the ketone/DCM layer becomes a strange, thick reddish-brown with green overtones. This happens as the NaOH pulls the majority of the solvated hydroquinone into its layer, cleaning the ketone. The NaOH layer in the first wash will be very dark brown, almost black in fact. The next two will be a far lighter, watery, orangy color.)
13. Dry the ketone/DCM solution with ~50g magnesium sulfate.
14. Distill off the DCM using mild heat on a water bath and ice-cold water through the condenser. This will take several hours.
15. Add 50mL of high-oleic safflower oil (no additives!!) to the ketone oil as a buffer to prevent the ketone from scorching in the distilling flask.
16. Vacuum distill the ketone from the ketone/buffer oil mixture. This can take several hours (around 6-8 hours at this scale, in my experience).
17. At 100 to 140°C (or wherever your particular vacuum dictates), a minor amount of safrole should come over. If your safrole-to-ketone conversion was good, there should only be a very small amount. If it is only a few drops to a milliliter or two, you can leave it in, and not change/clean receiving flasks. If you are a stickler for purity, discard it. It will not harm anything later if you leave it in. But if it’s more than a couple of milliliters, get rid of it.
18. At anywhere from 25 to 40°C above the temperature your safrole usually comes over with the same vacuum, the ketone should begin coming over. You should get about 100 to 120g ketone. The color of the ketone coming over should be a pale, fluorescent-looking greenish yellow. In fact it looks not unlike anti-freeze—a similar “neon green.” You can stop distilling when the rate of ketone coming over has slowed to an agonizing one drop per 90 seconds or so. At this point there is so little left that it is probably not worth your time to wait for a drop per 1.5 minutes (it’s not worth mine anyway).
19. Immediately store your precious fluid in the freezer in a sealed flask or bottle. Happy cooking!

posted 01-01-2000 02:56 PM         

Materials:
400mL MeOH (methanol)
50mL distilled H2O
150g p-Benzoquinone
2g palladium (II) chloride (PdCl2)
178g safrole
DCM (methylene chloride; dichloromethane)
NaCl (non-iodized table salt)
Sodium bicarbonate (baking soda)
5% NaOH
HCl (hydrochloric acid, from muriatic acid)
Magnesium sulfate drying agent (epsom salts baked in 400°F oven for 2 hours)

posted 01-01-2000 04:43 PM         

It's easier to get (one less item to be chem-supplier dependent on), much cheaper, and more pleasant to work with (DMF=stinky yucky pew) than DMF.

Methanol kicks ass!!! (especially if you drink some)(just kidding kiddies, don't try that at home!!)

posted 01-01-2000 04:46 PM         

U.T.F.S.E.

posted 01-04-2000 10:16 PM         

You are on fire and a saint to many bees here,.

I am just curious to see what kind of results you are getting on the amalgamation side of things,.

You previous post is perfect and accurate enough to follow be most bees,.
Would it be to much to ask, if you could write an amalgamation procedure based on true amounts, just like before,.

This would be superb,.

I haven't had much time to read other threads, so I am hoping that you haven't already answered this,.

Great thaks in advance

posted 01-08-2000 08:35 PM         

If that is the case, I do hope to hear something from you, at your discretion,.
It sure sounds like your having a good little time, whereever you are.I am glad that you are having a succeful new year,.

Be strong, stay safe my friend,.

hellman

Don't you think it would be great to find a replacement for p-benzoquinone,.
Like starting with napthalene or something,. I do remember vagely a post by chemhack or spicemacmachine???>

posted 01-12-2000 01:31 PM         

Should gentle heat be apply during the whole time of the refluxing. What should the temp be keep at.

10. Wash the ketone/DCM solution with saturated sodium bicarbonate in water twice (500mL each wash).
11. Wash the ketone/DCM solution with saturated NaCl 3 times (400-500mL each wash).

posted 01-12-2000 08:22 PM         

Bright Star: Thanks. But it wouldn't have been so easy without the Getafix writeup that I adapted it from. I have a neurotic fixation for the little details that are unfortunately lacking in most of the material out there. From my own (well, Mr. Agidk's) experience, I know how the neophyte craves those little details. Next I will write up my take on the MeNO2/Al/Hg reduction. I better hurry before it becomes a federal crime to do so.

Anyway BS you asked about the quality of the product: two thumbs up! Way up! (According to those who were in a postion to know.) Mr. Agidk needs 180-190 mg or so, but he's a hardhead and "normal" folks were fine with the more conservative dosages.

posted 01-20-2000 05:58 PM         

Now, since MeOH begins refluxing at about 58C, and all I suggest is a real mild, slow reflux (about one drop every four or five seconds), then I don't think that the temperature is really any higher than what is reached in the mildly exothermic DMF variation. For some reason, with DMF, there is some heat generated by the reaction, whereas with alcohols as the solvent, the reaction never really gets beyond warmth (even when the safrole addition is at its peak).

I would guess that if you didn't apply any heat, the reacion would work but with a lower yield. I think refluxing promotes an accelerated exchange of molecular activity (just a hunch).

posted 01-21-2000 07:39 AM         

Excellent work MM.

posted 01-21-2000 12:17 PM         

Bankrobber- The effect of the nice refluxing Temp is that a constant temp is maintained ... there is no variation of temperature.

posted 01-21-2000 12:29 PM         

------------------
O.G. Bankrobber Smashing Through The Night

posted 01-22-2000 12:27 AM         

To reflux or not to reflux, that is the question. All I can say is Mr. Agidk does, and gets very satisfying yields. No significant forerun of isosaf or saf whatsoever (well sometimes he gets about 20mL of that bright orange oil that you see floating in good Thai curries ). As I said, for me the idea came from seeing someone else suggest it here. I don't know shit about chemistry theory but it seems to me that refluxing would stimulate a more intimate relationship between molecules and thus would be a good idea when heat is not a concern. And why would it be a concern here? The way my simple mind sees it, if ketone can withstand temps like 200C once formed, then a measly 58-60C when forming should be of no concern at all.

I acknowledge your results Bankrobber, and someone else should try it with no heat at all as well and see if they get the same kind of results. If in the end it turns out that the reflux makes no difference, why do it? Myself, I love to eliminate steps and labor.

BTW Sunlight Mr. A just aminated some bright green stuff that came from just such a wacker and boom it definitely did its groove thang so there is more proof.

BS: thanks for the pat, however I really feel unworthy... I am a neophyte who is still learning and just sharing what I observe.

Oh and for those who may have been following the trials and tribulations of Mr. A who believed he was having crystallization failures due to H2O sneaking in, he has figured it out---he was way wrong. He was having amination failures <gasp!> due to incomplete amalgamation, and like a dummy was overlooking that and trying to crystallize anyway (what an absent-minded freak!). He has seen the light now however and has now found his way back to the ratios that work and will never EVER try to do things from memory, or tweak variables, again. Hallelujah.

posted 01-25-2000 02:13 AM         

scwam: In the fictional adventures of Mr. A there had been much heartache of late regarding (in the MeNO2/AlHg reduction) Hg salt amounts and the failures associated with not using enough. He was so confused he was misdiagnosing it as other things. He then finally found his way back to sure-fire ratios and what for him are TEXTBOOK reactions, and that being the case I intend to write a writeup for the hive within the next day or two that puts this very reliable, HARD-WON variation on record once and for all, complete with very helpful observations of some finer points that never get mentioned in the other writeups and posts. These are things that for a trained chemist would be second nature and not even thought about, but for fledgling DIY-bees are very important. And with all respect due to Mr. Ritter (without whom we would not even be talking about this), his original writeup contains a couple of things that for Mr. A at least did not really translate into reality. So look for that writeup in this forum in a day or two. Anyway scwam those amounts will all be in there and YES, the problem Mr. A was having was that he had gotten too cocky to take notes and lost the proper ratios for good reaction dynamics, falling into a bad cycle of using not enough HgCl2. All better now though! With great yields!

Sunlight: thank you sir, danke, dank u vel, merci, gracias, etc etc. Very nice to hear coming from your particular self.

Anyway I don't know how this thread digressed to reductions from benzo wackers, but what the fuck. It's all in fun (lonely teenagers notwithstanding ).