Author Topic: Newbie question  (Read 1156 times)

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abolt

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Newbie question
« on: November 11, 2002, 04:20:00 AM »
Hello good folks out there in the Hive, I am new to the Hive and, after extensive reading and research, am about to embark on my first synthesis. I am hoping I can get some feedback on a synthesis from RHODIUM’S site entitled “MDP2P FROM SAFROLE USING H2SO4 AND NH4NO3” which entails the following procedure:

Collect clean Safrole and chill to 0 c. in a freezer.
 Prepare 80% H2SO4 and also chill to 0.c in freezer.
Add 20g. CHILLED Safrole to 250ml. R.B.F, placed upon stirrer in ice/salt bath (-5.C).
Place CHILLED 80% H2SO4 in CHILLED drop funnel and add to Safrole at 3 drops per second.
After this addition, put 80ml. CHILLED DH20 in drop funnel and add to H2SO4/ALKENE at 3-4 drops per second.
 When finished place contents of 250ml. R.B.F. into sep. funnel, add salt, discard lower portion, dry over MG2SO4, to reveal 20-22 g. of MDP2Pol.
 Combine 20g. MDP2Pol to 20g. NH4SO3 and CHILL, in a R.B.F, in an ice bath, add 30 ml. G.A.A., a “dash” of CUPRIC ACETATE and 5 ml. DH2O.
Gently heat for 10-15 mins, cool mixture, filter, separate RAW MDP2P layer from liquid portion via 3x D.C.M., combine extracts, dry over MG2SO4 and evaporate D.C.M. to yield 20g. red/yellow oil.
Filter through SILICA/BUCHNER to yield 19-20g. MDP2P.

The write-up is incoherent and there is also a disclaimer questioning the validity of this process, so could anyone please let me know:

Does this process, in fact, work? And if so
Have I interpreted it correctly?
Can store bought AMMONIUM NITRATE be used?
If it has any additives will this affect this process?
Could dry ice be used in the cooling process or will this be too cold and freeze the DH2O/G.A.A. content?

If this works I am considering a LEUCKHART REACTION to convert my KETONE. The synthesis, also from the excellent RHODIUM site is listed below, I would appreciate any comments on this also (e.g. Is there a way I can get a better yield with my leuckhart than the proposed 70%). It goes as follows:

Add 4 parts KETONE, 11 parts FORMAMIDE, 0.2 parts G.A.A and 2 parts DH20 to a suitably sized distillation set-up with the thermometer reaching into the mix.
Heat oil-bath to 100. C and SLOWLY raise to 150.c to keep reaction moving along.
Let reaction cool, add vacuum Adapter and distill off  FORMAMIDE under vacuum.
Add 60 g. KOH to 160 ml. ETHANOL and 50 ml. DH20 to leftover residue and reflux for 20 mins.
Evaporate ETHANOL, filter over SILICA/BUCHNER, basify with 25% NAOH, extract with 3x D.C.M., combine extracts and dry over MG2SO4.
Yield is said to be 70%
Crystallize by SLOWLY dripping 100% I.P.A./H.C.L. to D.C.M/ M.D.A. and filter to collect crystals. Enjoy.

If these processes are both viable one could make up a beautiful batch of MDA/HCL in a few hours.

THANKS,     
PIHKALS & ICECREAM

Rhodium

  • Guest
NB!
« Reply #1 on: November 11, 2002, 05:06:00 AM »
We have gotten no reliable reports of anyone being able to prepare MDP2Pol from Safrole using H2SO4. If you don't have any analytic equipment to confirm its formation, then attempting this synthesis is a waste of time.

overclock

  • Guest
Can I get a reference to the procedure?
« Reply #2 on: November 11, 2002, 02:15:00 PM »
I'm too lazy to search his website. What kind of analytical equipment we talking? I have access to a Beckman HPLC, a Pharmacia FPLC, and several spectrophotometers. I haven't learned how to use them yet, but I have all the manuals! I'd love to be able to do qualitative and quantitative analysis on compounds I synth, any recommended reading material?

-oc

Signature-less, Again.

Rhodium

  • Guest
Safrole -> MDP2Pol
« Reply #3 on: November 11, 2002, 02:28:00 PM »
Alkenes can be hydrated to secondary alcohols in markovnikov fashion by cold 70% sulfuric acid (which first makes the sulfate ester), hydrolysis of this ester supposedly gives the alcohol. There are hundreds of references for this kind of reaction in the literature, just not on safrole (but other allylbenzenes has been used, drone posted a reference list a long time ago).

However, some experimenters report that they got no reaction, some report that a reaction indeed did take place, but that the alcohol dehydrated to isosafrole, and finally BrightStar, who claimed that MDP2Pol was indeed formed (verified with NMR), but that it rearranged overnight to MDP1Pol (MD-propiophenone). Noone has heard about that kind of rearrangement before (MDP2Pol is stable when prepared via oxymercuration), and noone can really find out why it is so hard to hydrate safrole, when the reaction is a classic textbook example.

We need someone with analytical equipment to find out what reaction parameters are needed for MDP2Pol to form. But still, if that would fail - we might still be able to construct a high-yielding isosafrole or MD-propiophenone out of it.

Starting point:

https://www.thevespiary.org/rhodium/Rhodium/chemistry/mdp2pol.html

- and TFSE is filled to the brim with discussions.

abolt

  • Guest
Second Part
« Reply #4 on: November 19, 2002, 08:59:00 PM »
Thanks for the the reply.
Could you also critique the second part about the LEUCKHART REACTION method. Or can you suggest a more efficient method.

Rhodium

  • Guest
If you want to perform a Leuckart reaction, Post ...
« Reply #5 on: November 19, 2002, 09:32:00 PM »
If you want to perform a Leuckart reaction,

Post 302161 (missing)

(Antoncho: "Leuckart with 92%+ overall yield", Methods Discourse)
seems to be the way to go. If you are open to other alternatives than the Leuckart, then you have several megabytes worth of routes to choose from at my page.