locrian
(Hive Bee) 08-17-02 02:05 No 346089 |
DMMDA-2 from dillapiole via benzo wacker | Bookmark | ||||||
Okay, well the route itself may not be novel, but the application of the route to the particluar substance seems to be, so if it belongs elsewhere, sorry, but fuck it I say. Nobody seems to read the methods forum ... Swinl used 90% pure Indian Dill Seed Oil as is (okay so he's a lazy fucker sometimes) in a standard style MM benzowacker. Prestirred PdCl2 (2g) in solvent for two shours, added benzo (150g) and dH2O and stirred for an additional hour. He dripped in about 180 mL over 1 hr. Near the end of addition, heat was applied and the mixture brought to 70C and refluxed there for 5 hrs. After this, the mix was filtered to remove solids as per usual, but interestingly, swinl noticed there was something else caught by the filter - crystals the gleamed a bit. He had never seen this with a benzo wacker of safrole. He thought it was probably isodillapiole b/c isosafrole is by-product normally, and isodillapiole forms crystals, you see what he means, right? Anyways, the acid was added as per usual and the crude oil collected. The acid water was then extracted with 400mL DCM 1x and then 100mL DCM 1x. This was pooled together with the crude oil and then washed 1x with sat. Sod. bicarb. (300mL), then 1x with sat. NaCl (300mL) and 3x with 5% NaOH (400mL) sol. to remove by-products of reaction. DCM was removed by distillation, vac. from aspirator was applied and vac. distillation was attempted. Heat was slowly increased with some oil bath monitoring. Put hotplate on full blast once oil was at 110C. Then swinl fell asleep like a stupid fuck (knew he should done some tweak, kicking himself in the ass for it) and when he awoke, nothing had come over and everything had polymerized like a mofo inside the flask (sucked ass to clean). The setup was checked twice for leaks, vac. grease used and teflon tape so that was fine. Normally, swinl's vac pulls Safrole at 115-120C and tone at ~150-160C. Opinions on what went wrong are of course welcome, here's my theories. One is that the oil maybe should have been vac. distilled to purity first. This would give swinl a good idea of where he should expect the ketone to come over. I think. Is it reasonable to assume that it would follow the same pattern as MDP2P in the temp increase generally being 25-30C? Oh, I guess that's my only theory, everything else is just questions, so here goes: 1. Is it possible that the reagents are causing one of those funky rings to form between the methoxy groups? I doubt it since I've read that dillapiole was okay in a strong base environment. But what about adding the acid? Could that be fucking things up? 2. Would a different acid possilby be better suited? ie - maybe using the 15% sulfuric with a little refluxing as in AB's DMMDA-2 synth writeup? I don't know if that's cool to do in this case or not but I would think it would be okay and it worked for the performic. 3. Was the heat too high for the reflux, was rxn. too short? 4. Is the vac. too weak? I know its weak and a oil pump vac. would be better, but swinl has to work with what he's got right now. Would a bisulphite and recrystallization work? Is the ketone crystals or liquid at room temp? I've read conflicting reports. 5. And finally, were those crystals that were filtered isodillapiole as suspected? Many thanks. |
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foxy2 (Distinctive Doe) 08-17-02 02:33 No 346095 |
NaOH | Bookmark | ||||||
Bet residual NaOH caused it to polymerize. I think you might also want a stronger vacuum pump to distill that. Those who give up essential liberties for temporary safety deserve neither liberty nor safety |
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locrian (Hive Bee) 08-17-02 19:40 No 346257 |
Reply to 'NaOH' | Bookmark | ||||||
Good call on the NaOH. Yeah, I was afraid of that with the vacuum. I think swinl might try hooking up a pressure washer to the aspirator. He'll try it again soon, gotta whip up some more glass first though. Fucking DEA/FDA bastards... |
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locrian (Hive Bee) 08-25-02 10:57 No 348771 |
Hey BTW | Bookmark | ||||||
Is it reasonable to assume that DMMDP2P will boil over 25-30C higher than dillapiole as with MDP2P/safrole? A smaller batch in a smaller flask would probably help prevent polymerization as well. But, yeah, does this '25-30C higher' thing apply to all ketone intermediates to amines or only certain ones, or how does that work exactly? |
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starlight (Hive Bee) 08-26-02 13:46 No 349157 |
smaller batch may not be better | Bookmark | ||||||
Antibody says in his writeup that yields of DMMP2P after distillation were lower with smaller batches due to greater polymerisation....see footnote 3: "Smaller batchs of ketone had much lower yeilds (ca 50%) due to polymerization during distillation. Smoke entering the reciver was witnessed with oil bath temperatures as low as 190°C. 185°C was the highest bath temperature that did not result in massive polymerization. Bisulfite purification with amounts less than 100mls might be prudent." |
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Osmium (Stoni's sexual toy) 08-26-02 18:33 No 349219 |
> does this '25-30C higher' thing apply to all ... | Bookmark | ||||||
> does this '25-30C higher' thing apply to all ketone > intermediates to amines or only certain ones While it certainly isn't scientifically correct to use this approximation all the time this rule of thumb will give you an idea of which temp range to expect during ketone distillation. I'm not fat just horizontally disproportionate. |
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locrian (Hive Bee) 08-28-02 15:11 No 350074 |
Reply to '> does this '25-30C higher' thing apply | Bookmark | ||||||
While it certainly isn't scientifically correct to use this approximation all the time this rule of thumb will give you an idea of which temp range to expect during ketone distillation. Thanks, Os. Thought so, but wanted to be sure. Give me a little credit though, please ...I realized it was just a rule of thumb. Especially if you consider that BP's are reduced proportionally to other BP's. What causes that rise from the oil to the ketone? And if this generally can be applied to ketones of this nature, then it would most likely be from the double bonded Oxygen that defines all ketones, right? Would it be safe then to assume that molecular weight is related to BP then? And could that also then account for the BP of dillapiole being higher than that of safrole (due to the two methoxy groups attached to the former)? Also, is this a rule that applies to benzene ring containing molecules, or ring-substitued molecules, or what defines the group of ketones this applies to exactly? I know this isn't the best forum to ask these questions and I'll look this info up in my friend's college chem. text book in a day or two, but if someone feels like educating me first, it would be much appreciated. Antibody says in his writeup that yields of DMMP2P after distillation were lower with smaller batches due to greater polymerisation....see footnote 3: Good looking out, but I did take that footnote into account already, I just can't logically figure out why that would occur yet...Here's my reasoning - which all credit is due to Nemo_Tenetur as he wrote in Post 347622 (Nemo_Tenetur: "Batch size is also important", Methods Discourse):
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